布尔类型
#布尔 True False #真 假 # and #True True -->true #Flase False -->false #True False -->fasle #or #True True -->true #Flase False -->false #True False -->true
字符串格式化:
%s 什么类型都可以
%d 只能是数值型的,它不保留小数,只取整数,如果写了字符串会报错
%f 只能是数值型的,保留小数,如果写了字符串会报错
import datetime name = input("欢迎登陆,请输入你的名字:") #接收输入的 #py2里面 raw_input() today = datetime.datetime.today() words5 = "欢迎登陆," + name + ",今天的日期是" + str(today) words6 = "欢迎登陆,%s,今天的日期是%s" % (name,today) print(words5) print(words6)
age = 5 sum = age + 1 number = age - 1 number2 = age * 3 number4 = age / 4 #正常,在python2里面它就是地板除,如果你要变成正常的除法,那么除数或者被除数要有一个是小数类型 number5 = age // 4 #地板除,只保留整数部分 number6 = 2**3 #取N次方的,2的3次方 number7 = 10 % 3 #取余,取模,取余数的意思 print(sum) print(number) print(number2) print(number4) print(number5) print(‘取次方的‘,number6) print(‘取余的结果‘,number7)
age = 10.123 # age2 = input("请输入你的年龄:")#input接收到的始终都是str类型 # age2 = int(age2) age2 = 10 # age2 = int( input("请输入你的年龄:")) #input接收到的始终都是str类型,需要转换成int类型 #int str float print("age的类型",type(age)) print("age2的类型",type(age2)) age3 = age + age2 print(age3) name = "aaa" #%s %d %f print("新的年龄是 %s" % age3)
数组增加、修改、删除等
students = "曾若天,吴康飞,刘慧杰" #数组,列表 stus = [ "曾若天","吴康飞","刘慧杰" ] # 下标 0 1 2 #取元素 print(stus) print(stus[-1]) #新增 stus.append("candy") stus.append("李雪松") stus.insert(0,"赵莹莹") stus.insert(2,"李兴培") #修改 stus[2] = "python" # stu = "111" # if stu in stus: # index = stus.index(stu) #如果查找不存在元素,会报错 # stus[index] = "邓金娇" # print(stus) #删除 stus.append("candy") print(stus) # stus.pop() #删除末尾的元素 # stus.pop(0)#删除指定下标的 # stus.remove("candy")#删除指定的元素,只删除第一个 # del stus[0] # print( stus.count("candy") )#查找元素出现的次数 nums = [82,23,235,236,121,1,0,3,25,26] # # nums.sort()#排序,默认是升序 # nums.sort(reverse=True)#排序,默认是升序,会改变原来list的值 # print(nums) # nums.reverse()#反转list,会改变原来list的值 # stus.clear()#清空list stus.extend(nums) #把另外一个list里面的元素都加入到一个list里面 print(stus)
#多维数组
l = [1,2,3,4,5,6,[7,8,9,10,11]] #2维数组 l2 = [1,2,3,4,5,6, [ 7,8,9,10,11,["zengruotian",‘abc‘]] ] #3维数组 print(l[-1][3]) print(l2[-1][-1][0])
#tuple l = [1,2,3] t = (1,2,3) print(t[0]) for i in t: print(i) info = ("118.23.3.40", "root", "123456", "3306") print(info.count("root")) print(info.index("root")) info = ("118.23.3.40", "root1", "123456", "3306") print(info)
# if xxx: # xxx # else: # xxxx username = "admin" password = "123456" username2 = "xiaohei" # # u = input("请输入用户名:") # p = input("请输入密码:") # # # if (u == username or u == username2) and p == password: # # print("登录成功,欢迎%s登录" % username) # # else: # # print("账号/密码错误!") # # if u == username or u == username2: # if p == password: # print("登录成功") # else: # print("密码错误") # else: # print("账号不存在") #账号输入admin和小黑都可以,密码是123456 # if u == username: # print("你是admin用户") # elif u == username2: # print("你是普通用户") # else: # print("用户名不正确") sex = input("请输入性别:") # print(len(sex)) #取长度 sex_str = "男女" # if sex in sex_str and len(sex) == 1: # print("性别合法") # else: # print("你可能不是地球人") if sex not in sex_str: print("不合法") elif len(sex) != 1: print("不合法") else: print("性别合法") # sex1 sex2 # if sex1 in sex_str or sex2 in sex_str: # if sex == "男" or sex == "女": # print("合法") # else: # print("你可能不是地球人") #比较运算符 # == # > # < # >= # <= # != #并且 或 and or #in 在xxx里面 #not 不
continue #如果在循环里面遇到continue,那么结束本次循环,立马进行下一次循环
break #如果在循环里面遇到break,循环立即结束,不管还有多少次没有循环
while 循环,使用循环的话需要定义一个计数器,用来控制循环次数
对应的else,如果循环是正常结束的,那么会执行else里面的代码,如果循环是被break结束的,不会执行
编译型
import random number = random.randint(1, 100) count = 7 while count > 0: count = count - 1 guess = input("请输入一个数字:") guess = int(guess) if guess == number: print("恭喜你猜对了,数字是%s" % number) break elif guess < number: print("猜小了,剩余%s次" % count) continue elif guess > number: print("猜大了,剩余%s次" % count) continue else: print("游戏结束,次数已经达到上限")
import random number = random.randint(1, 100) for i in range(7): guess = input("请输入一个数字:") guess = int(guess) if guess == number: print("恭喜你猜对了,数字是%s" % number) break elif guess < number: print("猜小了") continue elif guess > number: print("猜大了") continue
import os l = [‘赵莹莹‘, ‘曾若天‘, ‘python‘, ‘吴康飞‘, ‘刘慧杰‘, ‘candy‘, ‘李雪松‘] #麻烦的方式,计算下标去取值 index = 0 while index < len(l): name = l[index] os.mkdir(name) #创建文件夹 index = index + 1 for index in range(len(l)): print(l[index]) for name in l:#直接循环list,就是取list里面的每个元素 os.mkdir(name) print(name)
#写一个录入学生信息的程序, # 接收输入学生名称,判断学生是否存在,如果存在的话,提示已经存在,继续添加, #如果不存在的话,加入到list里面,继续添加 students = ["zengruotian","candy"] #list() while True: name = input("请输入学生名称:") if name == "quit": print("程序退出,现在的学生名单是",students) break elif students.count(name) == 0: students.append(name) print("添加成功,现在的学生名单是",students) continue else: print("学生已经存在,请重新输入")
continue #不存在的、存在的、quit
# 曾若天 18 180 150 北京 stdents = [ ["曾若天","18","180","150","北京"], ["liuhuijie","18","180","150","北京"], ["candy","18","180","150","北京"], ["lixuesong","18","180","150","北京"], ] student_info = { "addr": "北京", "name":"曾若天", "age":18, "high":180, "tizhong":150, } #增 # student_info["age"] = 19 # student_info["money"] = 300000 # student_info.setdefault("car","bmw") #如果是已经存在的key,setdefault不会修改已有的值 #修改 student_info["age"] = 19 #取值 # print(student_info["name"]) # print(student_info["age"]) # print(student_info.get("addr")) # print(student_info.get("tizhong")) #删除 # student_info.pop("age") # del student_info["age"] # student_info.popitem() #删除最后一个元素 #其他的方法 # student_info.clear() #清空 # d = {"phone":110} # student_info.update(d) #合并两个字典 # print(student_info.values()) # print(student_info.keys()) # print(student_info.items()) # # print("name" in student_info.keys()) # print("name" in student_info)#直接用in判断的话,就判断这个key是否存在 #student_info.has_key("name")#python2里面有,python3里面没有 # print(student_info) # for key in student_info:#直接循环字典,每次取的是字典的key,比较高效的方式 # value = student_info[key] # value2 = student_info.get(key) # print("%s -> %s" %(key,value)) # print("%s -> %s" %(key,value2)) # for key,value in student_info.items(): print("%s %s" %(key,value))
字典嵌套
info = { ‘lgy‘:{ ‘age‘:18, ‘addr‘:‘beijing‘, ‘cars‘:[‘bmw‘,‘ben-z‘,‘audi‘] }, ‘fd‘:{ ‘house‘:{ ‘bj‘:[‘海淀区‘,‘昌平区‘,‘朝阳区‘,‘西城区‘], ‘sh‘:[‘静安区‘,‘闸北区‘] }, ‘money‘:5000 } } info["lgy"]["cars"].append("tesla") # print(info) #方丹 海淀区房卖了,卖了500w index = info["fd"]["house"]["bj"].index("海淀区") info["fd"]["house"]["bj"].pop(index) # info["fd"]["house"]["bj"].remove("海淀区") info["fd"]["money"] = info["fd"]["money"]+500 info["fd"]["money"]+=500 print(info)
原文:https://www.cnblogs.com/li-jiaqiang/p/14673156.html