用Pylint规范化Python代码，附PyCharm配置

Pylint一个可以检查Python代码错误，执行代码规范的工具。它还可以对代码风格提出建议。

官网：https://pylint.readthedocs.io

默认情况，Pylint就已经随着Python安装好。在Python的scripts目录下。

找一段小程序试验一下Pylint，程序很简单。

 
  
   
    
   
   
    
     #!/usr/bin/env python
    
   
  

   
    
   
   
    
     # encoding: utf-8
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
    
     '''
    
   
  

   
    
   
   
    
     Created on 2017年2月4日
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
    
     @author: Arthur Guo
    
   
  

   
    
   
   
    
     '''
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
    
     N = 10
    
   
  

   
    
   
   
    
     YHTriangle = []
    
   
  

   
    
   
   
    
     for i in range(N): # 行
    
   
  

   
    
   
   
    
      YHTriangle.append([])
    
   
  

   
    
   
   
    
      if i == 0:
    
   
  

   
    
   
   
    
      YHTriangle[i].append(1) #第一行只有 1
    
   
  

   
    
   
   
    
      else:
    
   
  

   
    
   
   
    
      YHTriangle[i].append(1) #最左元素永远为 1
    
   
  

   
    
   
   
    
      YHTriangle[i].append(1) #
     最右元素永远为 1
    
   
  

   
    
   
   
    
      for j in range(1,i): #中间元素
    
   
  

   
    
   
   
    
      if i 
     <> 0 and i 
     <> 1:
    
   
  

   
    
   
   
    
      YHTriangle[i].insert(j,YHTriangle[i-1][j-1] + YHTriangle[i-1][j])
    
   
  

   
    
   
   
    
     for i in range(N):
    
   
  

   
    
   
   
    
      print YHTriangle[i]

命令行运行pylint yanghui.py，结果看起来很冗长

 
  
   
    
   
   
    
     c:\>c:\Python27\Scripts\pylint.exe d:\workspace\PyComm\src\Interviews\yanghui.py
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
    
     No config file found, using default configuration
    
   
  

   
    
   
   
    
     ************* Module Interviews.yanghui
    
   
  

   
    
   
   
    
     C: 19, 0: Exactly one space required after comma
    
   
  

   
    
   
   
    
      for j in range(1,i): #中间元素
    
   
  

   
    
   
   
    
      ^ (bad-whitespace)
    
   
  

   
    
   
   
    
     C: 21, 0: Exactly one space required after comma
    
   
  

   
    
   
   
    
      YHTriangle[i].insert(j,YHTriangle[i-1][j-1] + YHTriangle[i-1][j]
    
   
  

   
    
   
   
    
     )
    
   
  

   
    
   
   
    
      ^ (bad-whitespace)
    
   
  

   
    
   
   
    
     C: 23, 0: Final newline missing (missing-final-newline)
    
   
  

   
    
   
   
    
     C: 11, 0: Invalid constant name "YHTriangle" (invalid-name)
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
    
     Report
    
   
  

   
    
   
   
    
     ======
    
   
  

   
    
   
   
    
     13 statements analysed.
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
    
     Statistics by type
    
   
  

   
    
   
   
    
     ------------------
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
    
     +---------+-------+-----------+-----------+------------+---------+
    
   
  

   
    
   
   
    
     |type |number |old number |difference |%documented |%badname |
    
   
  

   
    
   
   
    
     +=========+=======+===========+===========+============+=========+
    
   
  

   
    
   
   
    
     |module |1 |1 |= |100.00 |0.00 |
    
   
  

   
    
   
   
    
     +---------+-------+-----------+-----------+------------+---------+
    
   
  

   
    
   
   
    
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     |type |number |% |previous |difference |
    
   
  

   
    
   
   
    
     +==========+=======+======+=========+===========+
    
   
  

   
    
   
   
    
     |code |15 |62.50 |15 |= |
    
   
  

   
    
   
   
    
     +----------+-------+------+---------+-----------+
    
   
  

   
    
   
   
    
     |docstring |5 |20.83 |5 |= |
    
   
  

   
    
   
   
    
     +----------+-------+------+---------+-----------+
    
   
  

   
    
   
   
    
     |comment |2 |8.33 |17 |-15.00 |
    
   
  

   
    
   
   
    
     +----------+-------+------+---------+-----------+
    
   
  

   
    
   
   
    
     |empty |2 |8.33 |3 |-1.00 |
    
   
  

   
    
   
   
    
     +----------+-------+------+---------+-----------+
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
    
     Duplication
    
   
  

   
    
   
   
    
     -----------
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
    
     +-------------------------+------+---------+-----------+
    
   
  

   
    
   
   
    
     | |now |previous |difference |
    
   
  

   
    
   
   
    
     +=========================+======+=========+===========+
    
   
  

   
    
   
   
    
     |nb duplicated lines |0 |0 |= |
    
   
  

   
    
   
   
    
     +-------------------------+------+---------+-----------+
    
   
  

   
    
   
   
    
     |percent duplicated lines |0.000 |0.000 |= |
    
   
  

   
    
   
   
    
     +-------------------------+------+---------+-----------+
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
    
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     |convention |4 |6 |-2.00 |
    
   
  

   
    
   
   
    
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     |message id |occurrences |
    
   
  

   
    
   
   
    
     +======================+============+
    
   
  

   
    
   
   
    
     |bad-whitespace |2 |
    
   
  

   
    
   
   
    
     +----------------------+------------+
    
   
  

   
    
   
   
    
     |missing-final-newline |1 |
    
   
  

   
    
   
   
    
     +----------------------+------------+
    
   
  

   
    
   
   
    
     |invalid-name |1 |
    
   
  

   
    
   
   
    
     +----------------------+------------+
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
    
     Global evaluation
    
   
  

   
    
   
   
    
     -----------------
    
   
  

   
    
   
   
    
     Your code has been rated at 6.92/10 (previous run: 5.38/10, +1.54)

‘’‘’Report

=======‘’‘’以上是Pylint对程序的建议，以下都是报告内容。多数时候，我们其实并不想看那么冗长的报告。这时候，体贴的Pylint就让我们屏蔽掉它们。

加上参数 --reports=n 或者更简单写成 -rn 就好了。再看检查结果：

 
  
   
    
   
   
    
     c:\>c:\Python27\Scripts\pylint.exe --reports=n d:\workspace\PyComm\src\Interview
    
   
  

   
    
   
   
    
     s\yanghui.py
    
   
  

   
    
   
   
    
     No config file found, using default configuration
    
   
  

   
    
   
   
    
     ************* Module Interviews.yanghui
    
   
  

   
    
   
   
    
     C: 19, 0: Exactly one space required after comma
    
   
  

   
    
   
   
    
      for j in range(1,i): #中间元素
    
   
  

   
    
   
   
    
      ^ (bad-whitespace)
    
   
  

   
    
   
   
    
     C: 21, 0: Exactly one space required after comma
    
   
  

   
    
   
   
    
      YHTriangle[i].insert(j,YHTriangle[i-1][j-1] + YHTriangle[i-1][j]
    
   
  

   
    
   
   
    
     )
    
   
  

   
    
   
   
    
      ^ (bad-whitespace)
    
   
  

   
    
   
   
    
     C: 23, 0: Final newline missing (missing-final-newline)
    
   
  

   
    
   
   
    
     C: 11, 0: Invalid constant name "YHTriangle" (invalid-name)

建议分三种：“bad-whitespace”, "missing-final-newline", "invalid-name".

前两个好说，加空格，加空行。但是下面这个怎么破？

C: 11, 0: Invalid constant name "YHTriangle" (invalid-name)

命名不规范？认为是个constant值？其实可以把这类问题忽略掉。

“Invalid constant name” 错误号是 C0103，所以加上 --disable=C0103即可。

 
  
   
    
   
   
    
     c:\>c:\Python27\Scripts\pylint.exe --reports=n --disable=c0103 d:\workspace\PyCo
    
   
  

   
    
   
   
    
     mm\src\Interviews\yanghui.py
    
   
  

   
    
   
   
    
     No config file found, using default configuration

没输出就是说名没问题了。

当然，还有更多的参数可以供选择。

=======================华丽丽的分割线===============================

平时写Python，我们几乎都不直接用命令行，而是用集成的IDE工具。比如猫哥常用的PyCharm。

Pylint官方文档提了可以支持PyCharm不过太简略了。

实际操作是这样的：

进入PyCharm，从菜单栏，依次进入： File -> Settings -> Tools -> External Tools。

“+”，进行添加。需要填写的部分分别是：“Name”，“Tool Settings -> Programs”、“Tool Settings -> Parameters”、“Tool Settings -> Working directory”。

注意：

“Parameters”里其它参数不管怎么写，必须在最后加上$FilePath$，“Working directory”里必须写 $FileDir$。

另外，需要再添加“Output Filter”，在上图中间靠右。填写内容的“Regular expression to match output”，必须是：$FILE_PATH$:$LINE$: 最后那个是冒号。

配置完毕，选择一个Python程序，右键点击，快捷菜单中会有“Extensions Tools -> Pylint”，点击运行即可。输出结果在执行程序结果的窗口（IDE下半部分）。

如果看到返回值为0，说明程序没问题了。

 
  
   
    
   
   
    
     C:\Python27\Scripts\pylint.exe --reports=n --disable=C0103 D:\PyCharmSpace\test1\test1\hello.py
    
   
  

   
    
   
   
    
     No config file found, using default configuration
    
   
  

   
    
   
   
     
    
   
  

   
    
   
   
    
     Process finished with exit code 0