用IDE写Python编写时有时会有标记，但是程序能正常运行，这里的标记是python编写不规范，下面给出一些规范写法。
一行列数 : PEP 8 规定为 79 列，这个太苛刻了，如果要拼接url一般都会超。
一个函数 : 不要超过 30 行代码, 即可显示在一个屏幕类，可以不使用垂直游标即可看到整个函数。
一个类 : 不要超过 200 行代码，不要有超过 10 个方法。
一个模块 : 不要超过 500 行。
不要在一句import中多个库
不推荐
import os, sys
推荐
import os
import sys
IDE显示的问题
错误记录：W292 no newline at end of file
处理：打个回车有新的一空行即可（新行不要有空格）。
错误记录：E302 expected 2 blank lines, found 1
处理：上面只有一行空白，但是需要两个空白行
错误记录：E231 missing whitespace after ‘,’
翻译：“，”后要有空格
举例：
错误 print(“%s %s %s %s %s %s” % (A,B,D,E,K,L))
正确 print(“%s %s %s %s %s %s” % (A, B, D, E, K, L))
错误记录：E225 missing whitespace around operator
翻译：
举例：
错误 print(“%s %s %s %s %s %s”%(A, B, D, E, K, L))
正确 rint(“%s %s %s %s %s %s”% (A, B, D, E, K, L))
错误记录：E225 missing whitespace around operator
举例：
错误 f=open(“D:\\test.txt”, “ab”)
正确 f = open(“D:\\test.txt”, “ab”)
更多错误记录：
| code | sample message |
|---|---|
| E1 | Indentation |
| E101 | indentation contains mixed spaces and tabs |
| E111 | indentation is not a multiple of four |
| E112 | expected an indented block |
| E113 | unexpected indentation |
| E114 | indentation is not a multiple of four (comment) |
| E115 | expected an indented block (comment) |
| E116 | unexpected indentation (comment) |
| E121 (*^) | continuation line under-indented for hanging indent |
| E122 (^) | continuation line missing indentation or outdented |
| E123 (*) | closing bracket does not match indentation of opening bracket’s line |
| E124 (^) | closing bracket does not match visual indentation |
| E125 (^) | continuation line with same indent as next logical line |
| E126 (*^) | continuation line over-indented for hanging indent |
| E127 (^) | continuation line over-indented for visual indent |
| E128 (^) | continuation line under-indented for visual indent |
| E129 (^) | visually indented line with same indent as next logical line |
| E131 (^) | continuation line unaligned for hanging indent |
| E133 (*) | closing bracket is missing indentation |
| E2 | Whitespace |
| E201 | whitespace after ‘(‘ |
| E202 | whitespace before ‘)’ |
| E203 | whitespace before ‘:’ |
| E211 | whitespace before ‘(‘ |
| E221 | multiple spaces before operator |
| E222 | multiple spaces after operator |
| E223 | tab before operator |
| E224 | tab after operator |
| E225 | missing whitespace around operator |
| E226 (*) | missing whitespace around arithmetic operator |
| E227 | missing whitespace around bitwise or shift operator |
| E228 | missing whitespace around modulo operator |
| E231 | missing whitespace after ‘,’, ‘;’, or ‘:’ |
| E241 (*) | multiple spaces after ‘,’ |
| E242 (*) | tab after ‘,’ |
| E251 | unexpected spaces around keyword / parameter equals |
| E261 | at least two spaces before inline comment |
| E262 | inline comment should start with ‘# ‘ |
| E265 | block comment should start with ‘# ‘ |
| E266 | too many leading ‘#’ for block comment |
| E271 | multiple spaces after keyword |
| E272 | multiple spaces before keyword |
| E273 | tab after keyword |
| E274 | tab before keyword |
| E275 | missing whitespace after keyword |
| E3 | Blank line |
| E301 | expected 1 blank line, found 0 |
| E302 | expected 2 blank lines, found 0 |
| E303 | too many blank lines (3) |
| E304 | blank lines found after function decorator |
| E305 | expected 2 blank lines after end of function or class |
| E4 | Import |
| E401 | multiple imports on one line |
| E402 | module level import not at top of file |
| E5 | Line length |
| E501 (^) | line too long (82 > 79 characters) |
| E502 | the backslash is redundant between brackets |
| E7 | Statement |
| E701 | multiple statements on one line (colon) |
| E702 | multiple statements on one line (semicolon) |
| E703 | statement ends with a semicolon |
| E704 (*) | multiple statements on one line (def) |
| E711 (^) | comparison to None should be ‘if cond is None:’ |
| E712 (^) | comparison to True should be ‘if cond is True:’ or ‘if cond:’ |
| E713 | test for membership should be ‘not in’ |
| E714 | test for object identity should be ‘is not’ |
| E721 (^) | do not compare types, use ‘isinstance()’ |
| E731 | do not assign a lambda expression, use a def |
| E741 | do not use variables named ‘l’, ‘O’, or ‘I’ |
| E742 | do not define classes named ‘l’, ‘O’, or ‘I’ |
| E743 | do not define functions named ‘l’, ‘O’, or ‘I’ |
| E9 | Runtime |
| E901 | SyntaxError or IndentationError |
| E902 | IOError |
| W1 | Indentation warning |
| W191 | indentation contains tabs |
| W2 | Whitespace warning |
| W291 | trailing whitespace |
| W292 | no newline at end of file |
| W293 | blank line contains whitespace |
| W3 | Blank line warning |
| W391 | blank line at end of file |
| W5 | Line break warning |
| W503 (*) | line break occurred before a binary operator |
| W6 | Deprecation warning |
| W601 | .has_key() is deprecated, use ‘in’ |
| W602 | deprecated form of raising exception |
| W603 | ‘<>’ is deprecated, use ‘!=’ |
| W604 | backticks are deprecated, use ‘repr()’ |
更多python编程规范：
http://blog.csdn.net/igolang/article/details/7886319
针对pycharm吧