python~type(获取变量类型)、help(某个函数或者类用法帮助文档) 、dir(类模块中可用函数)、查看文档

1.type（获取变量类型）

#encoding=utf-8

b = "test"

print(type(b)) #

脚本性语言，经常需要运行期间，来确定一个变量的类型，所以很常用。

 

2.help（某个函数或者类用法帮助文档）

#encoding=utf-8
import time
print (help(time))
"""
Help on module time:

NAME
    time - This module provides various functions to manipulate time values.

FILE
    /System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload/time.so

MODULE DOCS
    http://docs.python.org/library/time

DESCRIPTION
    There are two standard representations of time.  One is the number
    of seconds since the Epoch, in UTC (a.k.a. GMT).  It may be an integer
    or a floating point number (to represent fractions of seconds).
    The Epoch is system-defined; on Unix, it is generally January 1st, 1970.
    The actual value can be retrieved by calling gmtime(0).

    The other representation is a tuple of 9 integers giving local time.
    The tuple items are:
      year (four digits, e.g. 1998)
      month (1-12)
      day (1-31)
      hours (0-23)
...  
"""

print (help(time.sleep))

"""
Help on built-in function sleep in module time:

sleep(...)
    sleep(seconds)

    Delay execution for a given number of seconds.  The argument may be
    a floating point number for subsecond precision.
"""

help(time)可以详细查看time类的详细文档，包括它里面都有那些函数，函数的用法介绍等。

help(time.sleep) 可以更加详细查看模块中函数的参数。

 

3.dir(类模块中可用函数)

import time

print(dir(time))

"""
['__doc__', '__file__', '__name__', '__package__', 'accept2dyear', 'altzone', 'asctime', 'clock', 'ctime', 'daylight', 'gmtime', 'localtime', 'mktime', 'sleep', 'strftime', 'strptime', 'struct_time', 'time', 'timezone', 'tzname', 'tzset']
"""

可见，dir可以方便查询一个python模块，如time模块中，都有那些函数可以使用

 

4.查看python api文档

python -m pydoc -g