Python 经验总结

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1、StringIO模块，将输入测字符串作为流返回，可以进行迭代，示例如下：

# change the string to in memory stream, the detailed info can find in Python API

buf = StringIO(ret)

line_number = 0

for index, line in enumerate(buf.readlines()):

    if "is:" in line:

        line_number = index + 1

        break

status = buf.readlines()[line_number].strip()

2、re模块，正则表达式模块，示例如下：

# the regular expression below used for split string to a list by one or more whitespace.

for line in ret.split("\n"):

    if ‘rrc‘ in line and flag:

        flag = False

        column_of_rrc = re.split(r‘\s+‘, line.strip()).index(‘rrc‘)

        continue

    if "UEC-1  |" in line:

        stats = re.split(r‘\s+‘, line.strip())[column_of_rrc + 1]

        break

3、subprocess模块，用于启动操作系统上的shell命令行，并可以返回执行的结果

# with the subprocess to execute the command. 

# Popen.returncode 

# The child return code, set by poll() and wait() (and indirectly by communicate()). A None 

# value indicates that the process hasn’t terminated yet.



decode_result = subprocess.Popen(decode_cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)

start = datetime.datetime.now()

decode_log = "start to decode log.\n\r"

while decode_result.poll() is None:

    for line in decode_result.stdout.readlines():

        decode_log += line

    time.sleep(1)

    if (datetime.datetime.now() - start).seconds > timeout:

        failed_reason = "decode run timeout"

        self._log.error(failed_reason)

        rc = decode_result.returncode

        self._log.info("timeout,return code is %s" % rc)

        istimeout = True

        ctypes.windll.kernel32.TerminateProcess(int(decode_result._handle), -1)

        break

4、collections集合相关

# the use is special

from collections import Counter

print Counter("hello")

>>> Counter({‘l‘: 2, ‘h‘: 1, ‘e‘: 1, ‘o‘: 1})

5、 glob模块

# list all the file enb.py, can with wildchar, like * etc.

# glob.glob(‘*.py‘)  can list all file under current path endwiths .py

file_list = glob.glob("%s/*/enb.py" % os.path.dirname(os.path.abspath(__file__)))

6、os.path模块

# This used for deal with file and directory

os.path.dirname(‘C:/a/b‘) --> ‘C:/a‘

os.path.basename(‘C:/a/b‘) --> ‘b‘