軟件文檔或者源代碼文檔是指與軟件系統(tǒng)及其軟件工程過程有關(guān)聯(lián)的文本實體。文檔的類型包括軟件需求文檔，設(shè)計文檔，測試文檔，用戶手冊等。其中的需求文檔，設(shè)計文檔和測試文檔一般是在軟件開發(fā)過程中由開發(fā)者寫就的，而用戶手冊等非過程類文檔是由專門的非技術(shù)類寫作人員寫就的。
 
早期的軟件文檔主要指的是用戶手冊，根據(jù)Barker的定義，文檔是用來對軟件系統(tǒng)界面元素的設(shè)計、規(guī)劃和實現(xiàn)過程的記錄，以此來增強系統(tǒng)的可用性。而Forward則認為軟件文檔是被軟件工程師之間用作溝通交流的一種方式，溝通的信息主要是有關(guān)所開發(fā)的軟件系統(tǒng)。Parnas則強調(diào)文檔的權(quán)威性，他認為文檔應(yīng)該提供對軟件系統(tǒng)的精確描述。
 
綜上，我們可以將軟件文檔定義為：

1.文檔是一種對軟件系統(tǒng)的書面描述；
2.文檔應(yīng)當精確地描述軟件系統(tǒng)；
3.軟件文檔是軟件工程師之間用作溝通交流的一種方式；
4.文檔的類型有很多種，包括軟件需求文檔，設(shè)計文檔，測試文檔，用戶手冊等；
5.文檔的呈現(xiàn)方式有很多種，可以是傳統(tǒng)的書面文字形式或圖表形式，也可是動態(tài)的網(wǎng)頁形式

>>> dir(list)
['__add__', '__class__', '__contains__', '__delattr__', '__delitem__', '__delslice__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__getslice__', '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__iter__', '__le__', '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__reversed__', '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__sizeof__', '__str__', '__subclasshook__', 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort']

>>> help(list.__mul__)

Help on wrapper_descriptor:

__mul__(...)
    x.__mul__(n) <==> x*n

>>> print(list.__mul__.__doc__)     #與help(list.__mul__)顯示的內(nèi)容一致
x.__mul__(n) <==> x*n

>>> print(list.index.__doc__)       #查看index的文檔
L.index(value, [start, [stop]]) -> integer -- return first index of value.
Raises ValueError if the value is not present.

>>> def qiwsir():
...     """I like python"""
...     print " ...
>>> qiwsir()
http://qiwsir.github.io

>>> print(qiwsir.__doc__)   #用這種方法可以看自己寫的函數(shù)中的文檔
I like python

>>> help(qiwsir)            #其實就是調(diào)用__doc__顯示的內(nèi)容

Help on function qiwsir in module __main__:

qiwsir()
    I like python

#!/usr/bin/env python
#coding:utf-8

import random

number = random.randint(1,100)

guess = 0

while True:

    num_input = raw_input("please input one integer that is in 1 to 100:")
    guess +=1

    if not num_input.isdigit():
        print "Please input interger."
    elif int(num_input)<0 and int(num_input)>=100:
        print "The number should be in 1 to 100."
    else:
        if number==int(num_input):
            print "OK, you are good.It is only %d, then you successed."%guess
            break
        elif number>int(num_input):
            print "your number is more less."
        elif number<int(num_input):
            print "your number is bigger."
        else:
            print "There is something bad, I will not work"

"""
   This is a game.
   I am Qiwei.
   I like python.
   I am writing python articles in my website.
   My website is http://qiwsir.github.io
   You can learn python free in it.
"""

#!/usr/bin/env python
#coding:utf-8

import random

number = random.randint(1,100)

guess = 0

while True:

    num_input = raw_input("please input one integer that is in 1 to 100:")
    guess +=1

    if not num_input.isdigit():
        print "Please input interger."
    elif int(num_input)<0 and int(num_input)>=100:
        print "The number should be in 1 to 100."
    else:
        if number==int(num_input):
            print "OK, you are good.It is only %d, then you successed."%guess
            break
        elif number>int(num_input):
            print "your number is more less."
        elif number<int(num_input):
            print "your number is bigger."
        else:
            print "There is something bad, I will not work"