Le chemin pour apprendre Python pour les débutants

#!/usr/bin/python
# -*- coding: UTF-8 -*-

str = 'Hello World!'

print str # 输出完整字符串
print str[0] # 输出字符串中的第一个字符
print str[2:5] # 输出字符串中第三个至第五个之间的字符串
print str[2:] # 输出从第三个字符开始的字符串
print str * 2 # 输出字符串两次
print str + "TEST" # 输出连接的字符串

for（i=1;i<=n;++i）
{
for(j=1;j<=n;++j)
{
c[ i ][ j ]=0; //该步骤属于基本操作 执行次数：n^2
for(k=1;k<=n;++k)
c[ i ][ j ]+=a[ i ][ k ]*b[ k ][ j ]; //该步骤属于基本操作 执行次数：n^3
}
}

def square(x):
return x**2
>>> square
<function square at 0x031AA230>
>>> dir(square)
[&#39;__call__&#39;, &#39;__class__&#39;, &#39;__closure__&#39;, &#39;__code__&#39;, &#39;__defaults__&#39;, &#39;__delattr__&#39;, &#39;__dict__&#39;, &#39;__doc__&#39;, &#39;__format__&#39;,&#39;__get__&#39;, &#39;__getattribute__&#39;, &#39;__globals__&#39;, &#39;__hash__&#39;, &#39;__init__&#39;, &#39;__module__&#39;, &#39;__name__&#39;, &#39;__new__&#39;,&#39;__reduce__&#39;, &#39;__reduce_ex__&#39;, &#39;__repr__&#39;, &#39;__setattr__&#39;, &#39;__sizeof__&#39;, &#39;__str__&#39;, &#39;__subclasshook__&#39;,&#39;func_closure&#39;, &#39;func_code&#39;, &#39;func_defaults&#39;, &#39;func_dict&#39;, &#39;func_doc&#39;, &#39;func_globals&#39;, &#39;func_name&#39;]

import osnames = os.listdir(src)for name in names:
    srcname = os.path.join(src, name)
    fo = open(srcname, 'r')    for line in fo:        print line