Day2
危机感，现在的小孩太厉害了。如果我们不努力那就悲剧了。
先天没优势，没有竞争力，怎么破？
获取字典key,value以及for循环
读取内容，r: 文件内容读进内存，read(),readlines--------》读取并处理内容，将内容处理成可比较的数据类型 { “用户名”:{‘pwd’: ‘密码’, ‘登陆次数’:1}, “用户名”:{‘pwd’: ‘密码’, ‘登陆次数’:1}, “用户名”:{‘pwd’: ‘密码’, ‘登陆次数’:1}, } #文件内容 # 用户名|密码|登陆次数 # 用户名|密码|登录次数 Flag = True counter = 0 ‘‘Whiel flag: #三次失败，flag= False counter = counter + 1 if counter > 2 : break #次数比较 #用户名，密码比较 #取出所有用户名和输入的用户名比较： .keys(),raw_input,in #用户名不存在，直接出去 #用户名存在 #密码比较 如果密码匹配，成功 否则，登录次数+1，continue { “用户名”:{‘pwd’: ‘密码’, ‘登陆次数’:1}, “用户名”:{‘pwd’: ‘密码’, ‘登陆次数’:1}, “用户名”:{‘pwd’: ‘密码’, ‘登陆次数’:1}, } #把字典处理成大文件，写进去
总结：
字典部分理解不清楚，要补习。
对于变量的作用域，执行声明并在内存中存在，该变量就可以在下面的代码中使用。
if 1==1: name = ‘wupeiqi‘ print name
下面的结论对吗？
#外层变量，可以被内层变量使用
#内层变量，无法被外层变量使用
if 1==1 : name = {‘nm‘:123} for item in name : #首先判断，有没有下一个 #item = 元素 print item #nm print item # 只要在内存里面存在就可以用 print name
result = 值1 if 条件 else 值2
如果条件为真：result = 值1
如果条件为假：result = 值2
二进制，01
八进制，01234567
十进制，0123456789
十六进制，0123456789ABCDE
Python基础
对于Python，一切事物都是对象，对象基于类创建
所以，以下这些值都是对象： "wupeiqi"、38、[‘北京‘, ‘上海‘, ‘深圳‘]，并且是根据不同的类生成的对象。
# 创建project # 配置解释器 # 创建文件 # 执行： # run
# 设置断点再启用debug #debug
#
注意：有raw_input的时候是需要进入“console”模式下进行输入才可以继续断点。
对于Python,一切事物都是对象，对象基于类创建。
li = [11,33,44] print li print type(li) #变量类型 print dir (list) #输出类里面的属性和方法 print help(list) #打印帮助，把这个类的详细内容输出print help(类型名.功能名) 查看类中某功能的详细内容 #其他类同样
小技巧：使用IDE,如pycharm，可以输入”list”，按住ctrl键同时鼠标移动到该字符上，可以查看这个类的详细帮助。
xxx._方法_ #类的内置方法
xxx.方法 # 类的非内置方法
n1 = 1 n2 = 2 print n1 + n2 print n1.__add__(n2) #使用内置方法执行加操作 n1 = -9 print n1.__abs__() #使用类的内置方法执行取绝对值 print abs(n1)
所以，以下这些值都是对象： "wupeiqi"、38、[‘北京‘, ‘上海‘, ‘深圳‘]，并且是根据不同的类生成的对象。
如： 18、73、84
每一个整数都具备如下功能：
print help(int)
i = 10 print i i = int(10) #默认十进制表示 print i i = int("10", base = 2) #二进制表示 print i i = int ("f", base = 16) #十六进制表示 print i
#从源码看int方法
# class int(object): # """ # int(x=0) -> int or long # int(x, base=10) -> int or long 可以通过第二个参数修改int类型的进制格式（二进制，十进制，十六进制） # # Convert a number or string to an integer, or return 0 if no arguments # are given. If x is floating point, the conversion truncates towards zero. # If x is outside the integer range, the function returns a long instead. # # If x is not a number or if base is given, then x must be a string or # Unicode object representing an integer literal in the given base. The # literal can be preceded by ‘+‘ or ‘-‘ and be surrounded by whitespace. # The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to # interpret the base from the string as an integer literal. # >>> int(‘0b100‘, base=0) # 4 # """ # def bit_length(self): # real signature unknown; restored from __doc__ # """ # int.bit_length() -> int # # Number of bits necessary to represent self in binary. # >>> bin(37) # ‘0b100101‘ # >>> (37).bit_length() # 6 # """ # return 0 # # def conjugate(self, *args, **kwargs): # real signature unknown # """ Returns self, the complex conjugate of any int. """ # pass # # def __abs__(self): # real signature unknown; restored from __doc__ # """ x.__abs__() <==> abs(x) 取绝对值""" # pass # # def __add__(self, y): # real signature unknown; restored from __doc__ # """ x.__add__(y) <==> x+y """ # pass # # def __and__(self, y): # real signature unknown; restored from __doc__ # """ x.__and__(y) <==> x&y """ # pass # # def __cmp__(self, y): # real signature unknown; restored from __doc__ # """ x.__cmp__(y) <==> cmp(x,y) """ # """比较两个数字大小""" # pass # # def __coerce__(self, y): # real signature unknown; restored from __doc__ # """ x.__coerce__(y) <==> coerce(x, y) 把原来的数和新加的数生成一个元组""" # pass # # def __divmod__(self, y): # real signature unknown; restored from __doc__ # """ x.__divmod__(y) <==> divmod(x, y) 取余数 # 数据库共有99条数据，每个页面10条数据？共需要多少页 # """ a = 99 print a.__divmod__(10) # pass # # def __div__(self, y): # real signature unknown; restored from __doc__ # """ x.__div__(y) <==> x/y 取商""" a = 99 print a/10 # pass # # def __float__(self): # real signature unknown; restored from __doc__ # """ x.__float__() <==> float(x) 转换类型""" a = int(10) print type(a) b = a.__float__() print type(b) # pass # # def __floordiv__(self, y): # real signature unknown; restored from __doc__ # """ x.__floordiv__(y) <==> x//y 地板除，不保留小数点后面的数字，只是保留商""" print 5/2 print 5//2 print 5.0/2 print 5.0//2 # pass # # def __format__(self, *args, **kwargs): # real signature unknown # pass # # def __getattribute__(self, name): # real signature unknown; restored from __doc__ # """ x.__getattribute__(‘name‘) <==> x.name 面向对象关注，获取类的方法 # xxx.append # """ # pass # # def __getnewargs__(self, *args, **kwargs): # real signature unknown 自动传参数 # pass # # def __hash__(self): # real signature unknown; restored from __doc__ # """ x.__hash__() <==> hash(x) 用于比较 # 在字典查找中，用于快速定位/比较值大小""" i = 10 print i.__hash__() # pass # # def __hex__(self): # real signature unknown; restored from __doc__ # """ x.__hex__() <==> hex(x) 返回当前数字的十六进制 表示""" i = 22 print i.__hex__() # pass # # def __index__(self): # real signature unknown; restored from __doc__ # """ x[y:z] <==> x[y.__index__():z.__index__()] """ # pass # # def __init__(self, x, base=10): # known special case of int.__init__ # """构造方法 # int(x=0) -> int or long # int(x, base=10) -> int or long # # Convert a number or string to an integer, or return 0 if no arguments # are given. If x is floating point, the conversion truncates towards zero. # If x is outside the integer range, the function returns a long instead. # # If x is not a number or if base is given, then x must be a string or # Unicode object representing an integer literal in the given base. The # literal can be preceded by ‘+‘ or ‘-‘ and be surrounded by whitespace. # The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to # interpret the base from the string as an integer literal. # >>> int(‘0b100‘, base=0) # 4 # # (copied from class doc) # """ i = 10 i = int(10) #init 方法自动执行 # pass # # def __int__(self): # real signature unknown; restored from __doc__ # """ x.__int__() <==> int(x) 转换为整数""" # pass # # def __invert__(self): # real signature unknown; restored from __doc__ # """ x.__invert__() <==> ~x 取反 """ # pass # # def __long__(self): # real signature unknown; restored from __doc__ # """ x.__long__() <==> long(x) 转换为长整数""" # pass # # def __lshift__(self, y): # real signature unknown; restored from __doc__ # """ x.__lshift__(y) <==> x<<y 左移，位运算""" # pass # # def __mod__(self, y): # real signature unknown; restored from __doc__ # """ x.__mod__(y) <==> x%y 取模，余数""" # pass # # def __mul__(self, y): # real signature unknown; restored from __doc__ # """ x.__mul__(y) <==> x*y 乘法""" # pass # # def __neg__(self): # real signature unknown; restored from __doc__ # """ x.__neg__() <==> -x 负值""" i = 10 print i.__neg__() # pass # # @staticmethod # known case of __new__ # def __new__(S, *more): # real signature unknown; restored from __doc__ # """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ # pass # # def __nonzero__(self): # real signature unknown; restored from __doc__ # """ x.__nonzero__() <==> x != 0 非零，不等于零""" # pass # # def __oct__(self): # real signature unknown; restored from __doc__ # """ x.__oct__() <==> oct(x) 八进制表示一个数字""" # pass # # def __or__(self, y): # real signature unknown; restored from __doc__ # """ x.__or__(y) <==> x|y """ # pass # # def __pos__(self): # real signature unknown; restored from __doc__ # """ x.__pos__() <==> +x 正值""" # pass # # def __pow__(self, y, z=None): # real signature unknown; restored from __doc__ # """ x.__pow__(y[, z]) <==> pow(x, y[, z]) 次方""" i = 2 print i.__pow__(8) # pass # # def __radd__(self, y): # real signature unknown; restored from __doc__ # """ x.__radd__(y) <==> y+x x+y = y+x""" # pass # # def __rand__(self, y): # real signature unknown; restored from __doc__ # """ x.__rand__(y) <==> y&x """ # pass # # def __rdivmod__(self, y): # real signature unknown; restored from __doc__ # """ x.__rdivmod__(y) <==> divmod(y, x) """ # pass # # def __rdiv__(self, y): # real signature unknown; restored from __doc__ # """ x.__rdiv__(y) <==> y/x """ # pass # # def __repr__(self): # real signature unknown; restored from __doc__ # """ x.__repr__() <==> repr(x) 转换为解释器可读格式""" # pass # # def __rfloordiv__(self, y): # real signature unknown; restored from __doc__ # """ x.__rfloordiv__(y) <==> y//x 操作数换位，功能如上类似函数""" # pass # # def __rlshift__(self, y): # real signature unknown; restored from __doc__ # """ x.__rlshift__(y) <==> y<<x """ # pass # # def __rmod__(self, y): # real signature unknown; restored from __doc__ # """ x.__rmod__(y) <==> y%x """ # pass # # def __rmul__(self, y): # real signature unknown; restored from __doc__ # """ x.__rmul__(y) <==> y*x """ # pass # # def __ror__(self, y): # real signature unknown; restored from __doc__ # """ x.__ror__(y) <==> y|x """ # pass # # def __rpow__(self, x, z=None): # real signature unknown; restored from __doc__ # """ y.__rpow__(x[, z]) <==> pow(x, y[, z]) """ # pass # # def __rrshift__(self, y): # real signature unknown; restored from __doc__ # """ x.__rrshift__(y) <==> y>>x """ # pass # # def __rshift__(self, y): # real signature unknown; restored from __doc__ # """ x.__rshift__(y) <==> x>>y """ # pass # # def __rsub__(self, y): # real signature unknown; restored from __doc__ # """ x.__rsub__(y) <==> y-x """ # pass # # def __rtruediv__(self, y): # real signature unknown; restored from __doc__ # """ x.__rtruediv__(y) <==> y/x """ # pass # # def __rxor__(self, y): # real signature unknown; restored from __doc__ # """ x.__rxor__(y) <==> y^x """ # pass # # def __str__(self): # real signature unknown; restored from __doc__ # """ x.__str__() <==> str(x) 转换为人可读格式""" # pass # # def __sub__(self, y): # real signature unknown; restored from __doc__ # """ x.__sub__(y) <==> x-y """ # pass # # def __truediv__(self, y): # real signature unknown; restored from __doc__ # """ x.__truediv__(y) <==> x/y """ # pass # # def __trunc__(self, *args, **kwargs): # real signature unknown # """ Truncating an Integral returns itself. """ # pass # # def __xor__(self, y): # real signature unknown; restored from __doc__ # """ x.__xor__(y) <==> x^y """ # pass # # denominator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default # """the denominator of a rational number in lowest terms""" # # imag = property(lambda self: object(), lambda self, v: None, lambda self: None) # default # """the imaginary part of a complex number""" # # numerator = property(lambda self: object(), lambda self, v: None, lambda self: None) # default # """the numerator of a rational number in lowest terms""" # # real = property(lambda self: object(), lambda self, v: None, lambda self: None) # default # """the real part of a complex number"""
可能如：2147483649、9223372036854775807
每个长整型都具备如下功能：
long 参考int
如：3.14、2.88
每个浮点型都具备如下功能：
float 参考int
如：‘wupeiqi‘、‘alex‘
每个字符串都具备如下功能：
class str(basestring): """ str(object=‘‘) -> string Return a nice string representation of the object. If the argument is a string, the return value is the same object. """ def capitalize(self): """ 首字母变大写 """ """ S.capitalize() -> string Return a copy of the string S with only its first character capitalized. """ return "" def center(self, width, fillchar=None): """ 内容居中，width：总长度；fillchar：空白处填充内容，默认无 """ """ S.center(width[, fillchar]) -> string Return S centered in a string of length width. Padding is done using the specified fill character (default is a space) """ return "" def count(self, sub, start=None, end=None): """ 子序列个数 """ """ S.count(sub[, start[, end]]) -> int Return the number of non-overlapping occurrences of substring sub in string S[start:end]. Optional arguments start and end are interpreted as in slice notation. """ return 0 def decode(self, encoding=None, errors=None): """ 解码 """ """ S.decode([encoding[,errors]]) -> object Decodes S using the codec registered for encoding. encoding defaults to the default encoding. errors may be given to set a different error handling scheme. Default is ‘strict‘ meaning that encoding errors raise a UnicodeDecodeError. Other possible values are ‘ignore‘ and ‘replace‘ as well as any other name registered with codecs.register_error that is able to handle UnicodeDecodeErrors. """ return object() def encode(self, encoding=None, errors=None): """ 编码，针对unicode """ """ S.encode([encoding[,errors]]) -> object Encodes S using the codec registered for encoding. encoding defaults to the default encoding. errors may be given to set a different error handling scheme. Default is ‘strict‘ meaning that encoding errors raise a UnicodeEncodeError. Other possible values are ‘ignore‘, ‘replace‘ and ‘xmlcharrefreplace‘ as well as any other name registered with codecs.register_error that is able to handle UnicodeEncodeErrors. """ return object() def endswith(self, suffix, start=None, end=None): """ 是否以 xxx 结束 """ """ S.endswith(suffix[, start[, end]]) -> bool Return True if S ends with the specified suffix, False otherwise. With optional start, test S beginning at that position. With optional end, stop comparing S at that position. suffix can also be a tuple of strings to try. """ return False def expandtabs(self, tabsize=None): """ 将tab转换成空格，默认一个tab转换成8个空格 """ """ S.expandtabs([tabsize]) -> string Return a copy of S where all tab characters are expanded using spaces. If tabsize is not given, a tab size of 8 characters is assumed. """ return "" def find(self, sub, start=None, end=None): """ 寻找子序列位置，如果没找到，则异常 """ """ S.find(sub [,start [,end]]) -> int Return the lowest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation. Return -1 on failure. """ return 0 def format(*args, **kwargs): # known special case of str.format """ 字符串格式化，动态参数，将函数式编程时细说 """ """ S.format(*args, **kwargs) -> string Return a formatted version of S, using substitutions from args and kwargs. The substitutions are identified by braces (‘{‘ and ‘}‘). """ pass def index(self, sub, start=None, end=None): """ 子序列位置，如果没找到，则返回-1 """ S.index(sub [,start [,end]]) -> int Like S.find() but raise ValueError when the substring is not found. """ return 0 def isalnum(self): """ 是否是字母和数字 """ """ S.isalnum() -> bool Return True if all characters in S are alphanumeric and there is at least one character in S, False otherwise. """ return False def isalpha(self): """ 是否是字母 """ """ S.isalpha() -> bool Return True if all characters in S are alphabetic and there is at least one character in S, False otherwise. """ return False def isdigit(self): """ 是否是数字 """ """ S.isdigit() -> bool Return True if all characters in S are digits and there is at least one character in S, False otherwise. """ return False def islower(self): """ 是否小写 """ """ S.islower() -> bool Return True if all cased characters in S are lowercase and there is at least one cased character in S, False otherwise. """ return False def isspace(self): """ S.isspace() -> bool Return True if all characters in S are whitespace and there is at least one character in S, False otherwise. """ return False def istitle(self): """ S.istitle() -> bool Return True if S is a titlecased string and there is at least one character in S, i.e. uppercase characters may only follow uncased characters and lowercase characters only cased ones. Return False otherwise. """ return False def isupper(self): """ S.isupper() -> bool Return True if all cased characters in S are uppercase and there is at least one cased character in S, False otherwise. """ return False def join(self, iterable): """ 连接 """ """ S.join(iterable) -> string Return a string which is the concatenation of the strings in the iterable. The separator between elements is S. """ return "" def ljust(self, width, fillchar=None): """ 内容左对齐，右侧填充 """ """ S.ljust(width[, fillchar]) -> string Return S left-justified in a string of length width. Padding is done using the specified fill character (default is a space). """ return "" def lower(self): """ 变小写 """ """ S.lower() -> string Return a copy of the string S converted to lowercase. """ return "" def lstrip(self, chars=None): """ 移除左侧空白 """ """ S.lstrip([chars]) -> string or unicode Return a copy of the string S with leading whitespace removed. If chars is given and not None, remove characters in chars instead. If chars is unicode, S will be converted to unicode before stripping """ return "" def partition(self, sep): """ 分割，前，中，后三部分 """ """ S.partition(sep) -> (head, sep, tail) Search for the separator sep in S, and return the part before it, the separator itself, and the part after it. If the separator is not found, return S and two empty strings. """ pass def replace(self, old, new, count=None): """ 替换 """ """ S.replace(old, new[, count]) -> string Return a copy of string S with all occurrences of substring old replaced by new. If the optional argument count is given, only the first count occurrences are replaced. """ return "" def rfind(self, sub, start=None, end=None): """ S.rfind(sub [,start [,end]]) -> int Return the highest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation. Return -1 on failure. """ return 0 def rindex(self, sub, start=None, end=None): """ S.rindex(sub [,start [,end]]) -> int Like S.rfind() but raise ValueError when the substring is not found. """ return 0 def rjust(self, width, fillchar=None): """ S.rjust(width[, fillchar]) -> string Return S right-justified in a string of length width. Padding is done using the specified fill character (default is a space) """ return "" def rpartition(self, sep): """ S.rpartition(sep) -> (head, sep, tail) Search for the separator sep in S, starting at the end of S, and return the part before it, the separator itself, and the part after it. If the separator is not found, return two empty strings and S. """ pass def rsplit(self, sep=None, maxsplit=None): """ S.rsplit([sep [,maxsplit]]) -> list of strings Return a list of the words in the string S, using sep as the delimiter string, starting at the end of the string and working to the front. If maxsplit is given, at most maxsplit splits are done. If sep is not specified or is None, any whitespace string is a separator. """ return [] def rstrip(self, chars=None): """ S.rstrip([chars]) -> string or unicode Return a copy of the string S with trailing whitespace removed. If chars is given and not None, remove characters in chars instead. If chars is unicode, S will be converted to unicode before stripping """ return "" def split(self, sep=None, maxsplit=None): """ 分割， maxsplit最多分割几次 """ """ S.split([sep [,maxsplit]]) -> list of strings Return a list of the words in the string S, using sep as the delimiter string. If maxsplit is given, at most maxsplit splits are done. If sep is not specified or is None, any whitespace string is a separator and empty strings are removed from the result. """ return [] def splitlines(self, keepends=False): """ 根据换行分割 """ """ S.splitlines(keepends=False) -> list of strings Return a list of the lines in S, breaking at line boundaries. Line breaks are not included in the resulting list unless keepends is given and true. """ return [] def startswith(self, prefix, start=None, end=None): """ 是否起始 """ """ S.startswith(prefix[, start[, end]]) -> bool Return True if S starts with the specified prefix, False otherwise. With optional start, test S beginning at that position. With optional end, stop comparing S at that position. prefix can also be a tuple of strings to try. """ return False def strip(self, chars=None): """ 移除两段空白 """ """ S.strip([chars]) -> string or unicode Return a copy of the string S with leading and trailing whitespace removed. If chars is given and not None, remove characters in chars instead. If chars is unicode, S will be converted to unicode before stripping """ return "" def swapcase(self): """ 大写变小写，小写变大写 """ """ S.swapcase() -> string Return a copy of the string S with uppercase characters converted to lowercase and vice versa. """ return "" def title(self): """ S.title() -> string Return a titlecased version of S, i.e. words start with uppercase characters, all remaining cased characters have lowercase. """ return "" def translate(self, table, deletechars=None): """ 转换，需要先做一个对应表，最后一个表示删除字符集合 intab = "aeiou" outtab = "12345" trantab = maketrans(intab, outtab) str = "this is string example....wow!!!" print str.translate(trantab, ‘xm‘) """ """ S.translate(table [,deletechars]) -> string Return a copy of the string S, where all characters occurring in the optional argument deletechars are removed, and the remaining characters have been mapped through the given translation table, which must be a string of length 256 or None. If the table argument is None, no translation is applied and the operation simply removes the characters in deletechars. """ return "" def upper(self): """ S.upper() -> string Return a copy of the string S converted to uppercase. """ return "" def zfill(self, width): """方法返回指定长度的字符串，原字符串右对齐，前面填充0。""" """ S.zfill(width) -> string Pad a numeric string S with zeros on the left, to fill a field of the specified width. The string S is never truncated. """ return "" def _formatter_field_name_split(self, *args, **kwargs): # real signature unknown pass def _formatter_parser(self, *args, **kwargs): # real signature unknown pass def __add__(self, y): """ x.__add__(y) <==> x+y """ pass def __contains__(self, y): """ x.__contains__(y) <==> y in x """ pass def __eq__(self, y): """ x.__eq__(y) <==> x==y """ pass def __format__(self, format_spec): """ S.__format__(format_spec) -> string Return a formatted version of S as described by format_spec. """ return "" def __getattribute__(self, name): """ x.__getattribute__(‘name‘) <==> x.name """ pass def __getitem__(self, y): """ x.__getitem__(y) <==> x[y] """ pass def __getnewargs__(self, *args, **kwargs): # real signature unknown pass def __getslice__(self, i, j): """ x.__getslice__(i, j) <==> x[i:j] Use of negative indices is not supported. """ pass def __ge__(self, y): """ x.__ge__(y) <==> x>=y """ pass def __gt__(self, y): """ x.__gt__(y) <==> x>y """ pass def __hash__(self): """ x.__hash__() <==> hash(x) """ pass def __init__(self, string=‘‘): # known special case of str.__init__ """ str(object=‘‘) -> string Return a nice string representation of the object. If the argument is a string, the return value is the same object. # (copied from class doc) """ pass def __len__(self): """ x.__len__() <==> len(x) """ pass def __le__(self, y): """ x.__le__(y) <==> x<=y """ pass def __lt__(self, y): """ x.__lt__(y) <==> x<y """ pass def __mod__(self, y): """ x.__mod__(y) <==> x%y """ pass def __mul__(self, n): """ x.__mul__(n) <==> x*n """ pass @staticmethod # known case of __new__ def __new__(S, *more): """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ pass def __ne__(self, y): """ x.__ne__(y) <==> x!=y """ pass def __repr__(self): """ x.__repr__() <==> repr(x) """ pass def __rmod__(self, y): """ x.__rmod__(y) <==> y%x """ pass def __rmul__(self, n): """ x.__rmul__(n) <==> n*x """ pass def __sizeof__(self): """ S.__sizeof__() -> size of S in memory, in bytes """ pass def __str__(self): """ x.__str__() <==> str(x) """ pass str
name = "echo" print name.capitalize() #大写首字母 print name.center(20) #字长一定把字符放在中间 print name.center(30,"*") #字长一定把字符放在中间,用*替换空格 print name[0:1] #字符串切片 sname = "11124afsaljewoghgjaslmlsanhsalsjflsajflj" print sname.count("s",0,32) #统计字符串的子序列里面特定字符的个数
先使用decode解码，然后使用encode编码
>>> print str1.decode("gbk").encode("utf-8") 鏃
字符串的格式化操作
#使用数字做为占位符
>>> name = "i am {0}, your {1}" >>> name.format("echo","brother") ‘i am echo, your brother‘ #使用字符做为占位符
>>> name = "i am {ss}, your {dd}" >>> name.format(dd="echo",ss="brother") ‘i am brother, your echo‘
#占位符里面有列表的形式
>>> echo = ["hi","lee"] >>> name = "i am {0}, your {1}" >>> name.format(*echo) ‘i am hi, your lee‘ >>>
#字典形式需要加入 ** >>> dic = {"ss":"hi","dd":"echo"} >>> name = "i want to say {ss}, and {dd} i miss you" >>> name.format(**dic) ‘i want to say hi, and echo i miss you‘ >>>
注：编码&解码；字符串的乘法；字符串和格式化
>>> import string >>> input = "abcde" >>> output = "12345" >>> string.maketrans(input,output) ‘\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f !"#$%&\‘()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`12345fghijklmnopqrstuvwxyz{|}~\x7f\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff‘ >>> middlestr = string.maketrans(input,output) >>> mylist = "de,bc,ad,ee,dd,cc,bb" >>> mylist.translate(middlestr) ‘45,23,14,55,44,33,22‘ >>>
如：[11,22,33]、[‘wupeiqi‘, ‘alex‘]
每个列表都具备如下功能：
class list(object): """ list() -> new empty list list(iterable) -> new list initialized from iterable‘s items """ def append(self, p_object): # real signature unknown; restored from __doc__ """ L.append(object) -- append object to end """ pass def count(self, value): # real signature unknown; restored from __doc__ """ L.count(value) -> integer -- return number of occurrences of value """ return 0 def extend(self, iterable): # real signature unknown; restored from __doc__ """ L.extend(iterable) -- extend list by appending elements from the iterable
id不变""" pass def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__ """ L.index(value, [start, [stop]]) -> integer -- return first index of value. Raises ValueError if the value is not present. """ return 0 def insert(self, index, p_object): # real signature unknown; restored from __doc__ """ L.insert(index, object) -- insert object before index """ pass def pop(self, index=None): # real signature unknown; restored from __doc__ """ L.pop([index]) -> item -- remove and return item at index (default last). Raises IndexError if list is empty or index is out of range.
删除并返回指定下标的值，如果没有指定下标，那么删除最后一个
>>> li
[11, 99, 22, 33, 44, 11, 22, 33, 44]
>>> li.pop()
44
>>> li
[11, 99, 22, 33, 44, 11, 22, 33]
>>>
""" pass def remove(self, value): # real signature unknown; restored from __doc__ """ L.remove(value) -- remove first occurrence of value. Raises ValueError if the value is not present. """ pass def reverse(self): # real signature unknown; restored from __doc__ """ L.reverse() -- reverse *IN PLACE*
>>> li
[11, 99, 22, 33, 44, 11, 22, 33]
>>>
>>>
>>> li.reverse()
>>> li
[33, 22, 11, 44, 33, 22, 99, 11]
>>> li
[33, 22, 11, 44, 33, 22, 99, 11]
>>>
""" pass def sort(self, cmp=None, key=None, reverse=False): # real signature unknown; restored from __doc__ """ L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*; cmp(x, y) -> -1, 0, 1 """ pass def __add__(self, y): # real signature unknown; restored from __doc__ """ x.__add__(y) <==> x+y """ pass def __contains__(self, y): # real signature unknown; restored from __doc__ """ x.__contains__(y) <==> y in x """ pass def __delitem__(self, y): # real signature unknown; restored from __doc__ """ x.__delitem__(y) <==> del x[y] """ pass def __delslice__(self, i, j): # real signature unknown; restored from __doc__ """ x.__delslice__(i, j) <==> del x[i:j] Use of negative indices is not supported. """ pass def __eq__(self, y): # real signature unknown; restored from __doc__ """ x.__eq__(y) <==> x==y """ pass def __getattribute__(self, name): # real signature unknown; restored from __doc__ """ x.__getattribute__(‘name‘) <==> x.name """ pass def __getitem__(self, y): # real signature unknown; restored from __doc__ """ x.__getitem__(y) <==> x[y] """ pass def __getslice__(self, i, j): # real signature unknown; restored from __doc__ """ x.__getslice__(i, j) <==> x[i:j] Use of negative indices is not supported. """ pass def __ge__(self, y): # real signature unknown; restored from __doc__ """ x.__ge__(y) <==> x>=y """ pass def __gt__(self, y): # real signature unknown; restored from __doc__ """ x.__gt__(y) <==> x>y """ pass def __iadd__(self, y): # real signature unknown; restored from __doc__ """ x.__iadd__(y) <==> x+=y """ pass def __imul__(self, y): # real signature unknown; restored from __doc__ """ x.__imul__(y) <==> x*=y """ pass def __init__(self, seq=()): # known special case of list.__init__ """ list() -> new empty list list(iterable) -> new list initialized from iterable‘s items # (copied from class doc) """ pass def __iter__(self): # real signature unknown; restored from __doc__ """ x.__iter__() <==> iter(x) """ pass def __len__(self): # real signature unknown; restored from __doc__ """ x.__len__() <==> len(x) """ pass def __le__(self, y): # real signature unknown; restored from __doc__ """ x.__le__(y) <==> x<=y """ pass def __lt__(self, y): # real signature unknown; restored from __doc__ """ x.__lt__(y) <==> x<y """ pass def __mul__(self, n): # real signature unknown; restored from __doc__ """ x.__mul__(n) <==> x*n """ pass @staticmethod # known case of __new__ def __new__(S, *more): # real signature unknown; restored from __doc__ """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ pass def __ne__(self, y): # real signature unknown; restored from __doc__ """ x.__ne__(y) <==> x!=y """ pass def __repr__(self): # real signature unknown; restored from __doc__ """ x.__repr__() <==> repr(x) """ pass def __reversed__(self): # real signature unknown; restored from __doc__ """ L.__reversed__() -- return a reverse iterator over the list """ pass def __rmul__(self, n): # real signature unknown; restored from __doc__ """ x.__rmul__(n) <==> n*x """ pass def __setitem__(self, i, y): # real signature unknown; restored from __doc__ """ x.__setitem__(i, y) <==> x[i]=y """ pass def __setslice__(self, i, j, y): # real signature unknown; restored from __doc__ """ x.__setslice__(i, j, y) <==> x[i:j]=y Use of negative indices is not supported. """ pass def __sizeof__(self): # real signature unknown; restored from __doc__ """ L.__sizeof__() -- size of L in memory, in bytes """ pass __hash__ = None list
注：排序；
如：(11,22,33)、(‘wupeiqi‘, ‘alex‘)
每个元组都具备如下功能： 类似列表，不能被修改
元组的元素不能被修改（元组的元素的元素可以被修改）
tuple
如：{‘name‘: ‘wupeiqi‘, ‘age‘: 18} 、{‘host‘: ‘2.2.2.2‘, ‘port‘: 80}
ps：循环时，默认循环key
每个字典都具备如下功能：
class dict(object): """ dict() -> new empty dictionary dict(mapping) -> new dictionary initialized from a mapping object‘s (key, value) pairs dict(iterable) -> new dictionary initialized as if via: d = {} for k, v in iterable: d[k] = v dict(**kwargs) -> new dictionary initialized with the name=value pairs in the keyword argument list. For example: dict(one=1, two=2) """ def clear(self): # real signature unknown; restored from __doc__ """ 清除内容 """ """ D.clear() -> None. Remove all items from D. """ pass def copy(self): # real signature unknown; restored from __doc__ """ 浅拷贝 """ """ D.copy() -> a shallow copy of D """ pass @staticmethod # known case def fromkeys(S, v=None): # real signature unknown; restored from __doc__ """ dict.fromkeys(S[,v]) -> New dict with keys from S and values equal to v. v defaults to None. """ pass def get(self, k, d=None): # real signature unknown; restored from __doc__ """ 根据key获取值，d是默认值 """ """ D.get(k[,d]) -> D[k] if k in D, else d. d defaults to None. """ pass def has_key(self, k): # real signature unknown; restored from __doc__ """ 是否有key """ """ D.has_key(k) -> True if D has a key k, else False """ return False def items(self): # real signature unknown; restored from __doc__ """ 所有项的列表形式 """ """ D.items() -> list of D‘s (key, value) pairs, as 2-tuples """ return [] def iteritems(self): # real signature unknown; restored from __doc__ """ 项可迭代 """ """ D.iteritems() -> an iterator over the (key, value) items of D """ pass def iterkeys(self): # real signature unknown; restored from __doc__ """ key可迭代 """ """ D.iterkeys() -> an iterator over the keys of D """ pass def itervalues(self): # real signature unknown; restored from __doc__ """ value可迭代 """ """ D.itervalues() -> an iterator over the values of D """ pass def keys(self): # real signature unknown; restored from __doc__ """ 所有的key列表 """ """ D.keys() -> list of D‘s keys """ return [] def pop(self, k, d=None): # real signature unknown; restored from __doc__ """ 获取并在字典中移除 """ """ D.pop(k[,d]) -> v, remove specified key and return the corresponding value. If key is not found, d is returned if given, otherwise KeyError is raised """ pass def popitem(self): # real signature unknown; restored from __doc__ """ 获取并在字典中移除 """ """ D.popitem() -> (k, v), remove and return some (key, value) pair as a 2-tuple; but raise KeyError if D is empty. """ pass def setdefault(self, k, d=None): # real signature unknown; restored from __doc__ """ 如果key不存在，则创建，如果存在，则返回已存在的值且不修改 """ """ D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D """ pass def update(self, E=None, **F): # known special case of dict.update """ 更新 {‘name‘:‘alex‘, ‘age‘: 18000} [(‘name‘,‘sbsbsb‘),] """ """ D.update([E, ]**F) -> None. Update D from dict/iterable E and F. If E present and has a .keys() method, does: for k in E: D[k] = E[k] If E present and lacks .keys() method, does: for (k, v) in E: D[k] = v In either case, this is followed by: for k in F: D[k] = F[k] """ pass def values(self): # real signature unknown; restored from __doc__ """ 所有的值 """ """ D.values() -> list of D‘s values """ return [] def viewitems(self): # real signature unknown; restored from __doc__ """ 所有项，只是将内容保存至view对象中 """ """ D.viewitems() -> a set-like object providing a view on D‘s items """ pass def viewkeys(self): # real signature unknown; restored from __doc__ """ D.viewkeys() -> a set-like object providing a view on D‘s keys """ pass def viewvalues(self): # real signature unknown; restored from __doc__ """ D.viewvalues() -> an object providing a view on D‘s values """ pass def __cmp__(self, y): # real signature unknown; restored from __doc__ """ x.__cmp__(y) <==> cmp(x,y) """ pass def __contains__(self, k): # real signature unknown; restored from __doc__ """ D.__contains__(k) -> True if D has a key k, else False """ return False def __delitem__(self, y): # real signature unknown; restored from __doc__ """ x.__delitem__(y) <==> del x[y] """ pass def __eq__(self, y): # real signature unknown; restored from __doc__ """ x.__eq__(y) <==> x==y """ pass def __getattribute__(self, name): # real signature unknown; restored from __doc__ """ x.__getattribute__(‘name‘) <==> x.name """ pass def __getitem__(self, y): # real signature unknown; restored from __doc__ """ x.__getitem__(y) <==> x[y] """ pass def __ge__(self, y): # real signature unknown; restored from __doc__ """ x.__ge__(y) <==> x>=y """ pass def __gt__(self, y): # real signature unknown; restored from __doc__ """ x.__gt__(y) <==> x>y """ pass def __init__(self, seq=None, **kwargs): # known special case of dict.__init__ """ dict() -> new empty dictionary dict(mapping) -> new dictionary initialized from a mapping object‘s (key, value) pairs dict(iterable) -> new dictionary initialized as if via: d = {} for k, v in iterable: d[k] = v dict(**kwargs) -> new dictionary initialized with the name=value pairs in the keyword argument list. For example: dict(one=1, two=2) # (copied from class doc) """ pass def __iter__(self): # real signature unknown; restored from __doc__ """ x.__iter__() <==> iter(x) """ pass def __len__(self): # real signature unknown; restored from __doc__ """ x.__len__() <==> len(x) """ pass def __le__(self, y): # real signature unknown; restored from __doc__ """ x.__le__(y) <==> x<=y """ pass def __lt__(self, y): # real signature unknown; restored from __doc__ """ x.__lt__(y) <==> x<y """ pass @staticmethod # known case of __new__ def __new__(S, *more): # real signature unknown; restored from __doc__ """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ pass def __ne__(self, y): # real signature unknown; restored from __doc__ """ x.__ne__(y) <==> x!=y """ pass def __repr__(self): # real signature unknown; restored from __doc__ """ x.__repr__() <==> repr(x) """ pass def __setitem__(self, i, y): # real signature unknown; restored from __doc__ """ x.__setitem__(i, y) <==> x[i]=y """ pass def __sizeof__(self): # real signature unknown; restored from __doc__ """ D.__sizeof__() -> size of D in memory, in bytes """ pass __hash__ = None dict
>>>
>>> dic = {"ki":123}
>>> print dic.get("kk","hi")
hi
>>>
练习：元素分类 有如下值集合 [11,22,33,44,55,66,77,88,99,90...]，将所有大于 66 的值保存至字典的第一个key中，将小于 66 的值保存至第二个key的值中。 即： {‘k1‘: 大于66 , ‘k2‘: 小于66}
set是一个无序且不重复的元素集合
set
练习：寻找差异 # 数据库中原有 old_dict = { "#1":{ ‘hostname‘:c1, ‘cpu_count‘: 2, ‘mem_capicity‘: 80 }, "#2":{ ‘hostname‘:c1, ‘cpu_count‘: 2, ‘mem_capicity‘: 80 } "#3":{ ‘hostname‘:c1, ‘cpu_count‘: 2, ‘mem_capicity‘: 80 } } # cmdb 新汇报的数据 new_dict = { "#1":{ ‘hostname‘:c1, ‘cpu_count‘: 2, ‘mem_capicity‘: 800 }, "#3":{ ‘hostname‘:c1, ‘cpu_count‘: 2, ‘mem_capicity‘: 80 } "#4":{ ‘hostname‘:c2, ‘cpu_count‘: 2, ‘mem_capicity‘: 80 } } 需要删除：？ 需要新建：？ 需要更新：？ 注意：无需考虑内部元素是否改变，只要原来存在，新汇报也存在，就是需要更新
1、计数器（counter）
Counter是对字典类型的补充，用于追踪值的出现次数。
ps：具备字典的所有功能 + 自己的功能
c = Counter(‘abcdeabcdabcaba‘)
print c
输出：Counter({‘a‘: 5, ‘b‘: 4, ‘c‘: 3, ‘d‘: 2, ‘e‘: 1})
Counter
2、有序字典(orderedDict )
orderdDict是对字典类型的补充，他记住了字典元素添加的顺序
OrderedDict
3、默认字典(defaultdict)
学前需求：
1
2 有如下值集合 [11,22,33,44,55,66,77,88,99,90...]，将所有大于 66 的值保存至字典的第一个key中，将小于 66 的值保存至第二个key的值中。
即： {‘k1‘: 大于66 , ‘k2‘: 小于66}
原生字典解决方法
defaultdict字典解决方法
defaultdict是对字典的类型的补充，他默认给字典的值设置了一个类型。
defaultdict
4、可命名元组(namedtuple)
根据nametuple可以创建一个包含tuple所有功能以及其他功能的类型。
import collections
Mytuple = collections.namedtuple(‘Mytuple‘,[‘x‘, ‘y‘, ‘z‘])
Mytuple
5、双向队列(deque)
一个线程安全的双向队列
deque
注：既然有双向队列，也有单项队列（先进先出 FIFO ）
Queue.Queue
对于Python 列表的 for 循环，他的内部原理：查看下一个元素是否存在，如果存在，则取出，如果不存在，则报异常 StopIteration。（python内部对异常已处理）
listiterator
range不是生成器 和 xrange 是生成器
readlines不是生成器 和 xreadlines 是生成器
>>> print range(10) [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] >>> print xrange(10) xrange(10)
生成器内部基于yield创建，即：对于生成器只有使用时才创建，从而不避免内存浪费
练习：<br>有如下列表： [13, 22, 6, 99, 11] 请按照一下规则计算： 13 和 22 比较，将大的值放在右侧，即：[13, 22, 6, 99, 11] 22 和 6 比较，将大的值放在右侧，即：[13, 6, 22, 99, 11] 22 和 99 比较，将大的值放在右侧，即：[13, 6, 22, 99, 11] 99 和 42 比较，将大的值放在右侧，即：[13, 6, 22, 11, 99,] 13 和 6 比较，将大的值放在右侧，即：[6, 13, 22, 11, 99,] ...
为什么要拷贝？
1 当进行修改时，想要保留原来的数据和修改后的数据
数字字符串 和 集合 在修改时的差异？ （深浅拷贝不同的终极原因）
在修改数据时：
数字字符串：在内存中新建一份数据
集合：修改内存中的同一份数据
对于集合，如何保留其修改前和修改后的数据？
1 在内存中拷贝一份
对于集合，如何拷贝其n层元素同时拷贝？
1 深拷贝
开发一个简单的计算器程序
*实现对加减乘除、括号优先级的解析,并实现正确运算
原文：http://www.cnblogs.com/echorep/p/4931594.html