Python 模块【基础学习】

╰半夏微凉° 2022-08-07 13:51 182阅读 0赞

python Module（模块）

在计算机开发的过程中，随着程序代码越写越多，在一个文件里代码就会越来越长，越来越不容易维护。

为了编写可维护的代码，我们把很多函数分组，分别放到不同的文件里，这样，每个文件包含的代码就相对较少，很多编程语言都采用这种组织代码的方式。在Python中，一个.py文件就称之为一个模块（Module）。

使用模块有什么好处呢？

最大的好处是大大提高了代码的可维护性。其次，编写的代码不必从零开始。当一个模块编写，就可以被其他地方引用。我们在编写程序的时候，也经常引用其他模块，包含Python内置的模块和来自第三方的模块。

使用模块还可以避免函数名和变量名冲突。相同名字的函数和变量完全可以分别存在不同的模块中。

python内置函数：

<table style="border:0px solid rgb(221,204,238); border-collapse:collapse; color:rgb(0,0,0); font-family:sans-serif; font-size:16px"> 
 <tbody> 
 <tr></tr> 
 </tbody> 
 <thead> 
 <tr> 
 <th style="text-align:center; padding:2px 5px; background-color:rgb(238,221,238); border-left-width:0px; border-top-width:1px; border-top-style:solid; border-top-color:rgb(204,170,204)"> </th> 
 <th style="text-align:center; padding:2px 5px; background-color:rgb(238,221,238); border-left-width:0px; border-top-width:1px; border-top-style:solid; border-top-color:rgb(204,170,204)"> Built-in Functions</th> 
 <th style="text-align:center; padding:2px 5px; background-color:rgb(238,221,238); border-left-width:0px; border-top-width:1px; border-top-style:solid; border-top-color:rgb(204,170,204)"> </th> 
 <th style="text-align:center; padding:2px 5px; background-color:rgb(238,221,238); border-left-width:0px; border-top-width:1px; border-top-style:solid; border-top-color:rgb(204,170,204)"> </th> 
 </tr> 
 </thead> 
 <tbody> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#abs" title="abs" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">abs()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#divmod" title="divmod" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">divmod()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#input" title="input" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">input()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#open" title="open" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">open()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#staticmethod" title="staticmethod" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">staticmethod()</a></td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#all" title="all" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">all()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#enumerate" title="enumerate" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">enumerate()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#int" title="int" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">int()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#ord" title="ord" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">ord()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#str" title="str" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">str()</a></td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#any" title="any" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">any()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#eval" title="eval" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">eval()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#isinstance" title="isinstance" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">isinstance()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#pow" title="pow" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">pow()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#sum" title="sum" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">sum()</a></td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#basestring" title="basestring" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">basestring()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#execfile" title="execfile" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">execfile()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#issubclass" title="issubclass" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">issubclass()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#print" title="print" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">print()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#super" title="super" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">super()</a></td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#bin" title="bin" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">bin()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#file" title="file" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">file()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#iter" title="iter" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">iter()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#property" title="property" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">property()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#tuple" title="tuple" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">tuple()</a></td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#bool" title="bool" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">bool()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#filter" title="filter" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">filter()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#len" title="len" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">len()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#range" title="range" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">range()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#type" title="type" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">type()</a></td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#bytearray" title="bytearray" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">bytearray()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#float" title="float" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">float()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#list" title="list" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">list()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#raw_input" title="raw_input" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">raw_input()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#unichr" title="unichr" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">unichr()</a></td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#callable" title="callable" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">callable()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#format" title="format" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">format()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#locals" title="locals" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">locals()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#reduce" title="reduce" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">reduce()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#unicode" title="unicode" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">unicode()</a></td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#chr" title="chr" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">chr()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#func-frozenset" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">frozenset()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#long" title="long" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">long()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#reload" title="reload" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">reload()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#vars" title="vars" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">vars()</a></td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#classmethod" title="classmethod" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">classmethod()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#getattr" title="getattr" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">getattr()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#map" title="map" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">map()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#func-repr" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">repr()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#xrange" title="xrange" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">xrange()</a></td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#cmp" title="cmp" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">cmp()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#globals" title="globals" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">globals()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#max" title="max" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">max()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#reversed" title="reversed" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">reversed()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#zip" title="zip" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">zip()</a></td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#compile" title="compile" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">compile()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#hasattr" title="hasattr" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">hasattr()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#func-memoryview" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">memoryview()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#round" title="round" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">round()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#__import__" title="__import__" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">__import__()</a></td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#complex" title="complex" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">complex()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#hash" title="hash" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">hash()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#min" title="min" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">min()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#func-set" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">set()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> </td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#delattr" title="delattr" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">delattr()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#help" title="help" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">help()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#next" title="next" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">next()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#setattr" title="setattr" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">setattr()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> </td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#func-dict" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">dict()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#hex" title="hex" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">hex()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#object" title="object" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">object()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#slice" title="slice" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">slice()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> &nbsp;</td> 
 </tr> 
 <tr> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#dir" title="dir" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">dir()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#id" title="id" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">id()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#oct" title="oct" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">oct()</a></td> 
 <td style="padding:2px 5px; border-left-width:0px; background-color:rgb(238,238,255)"> <a href="https://docs.python.org/2/library/functions.html#sorted" title="sorted" style="color:rgb(53,95,124); text-decoration:none" rel="nofollow">sorted()</a> </td> 
 </tr> 
 </tbody> 
</table>

当你编写的模块名与别人同名了怎么办？为了避免模块名冲突，Python又引入了按目录来组织模块的方法，称为包（Package）。

举个例子：一个abc.py文件就是一个名字叫abc的模块，一个xyz.py的文件就是一个名字叫xyz.py的模块。

注意：每一个包目录下面都会有一个\_init\_.py的文件，这个文件是必须存在的，否则，Python就把这个目录当成普通目录，而不是一个包。\_init\_.py可以是空文件，也可以有Python代码，因为\_init\_.py本身就是一个模块。