【Python】72行实现代码行数统计，简单实用！

0. 前言

最近突然想知道自己总共写了多少行代码，于是做了这样一个小工具……

1. 准备工作

先考虑一下希望得到的效果：

Language（语言）	Lines（代码行数）	Size（代码文件总大小）	Files（代码文件总数）
A	12345	300 KB	193
B	2345	165 KB	98
如上，程序输出一个表格，将代码行数作为关键字排序。
代码框架：

# -*- encoding: utf-8 -*-
import ...# 代码行数计数类
class CodeLinesCounter(object):SIZES = [('B', 1), ('KB', 1024), ('MB', 1024**2), ('GB', 1024**3), ('TB', 1024**4)]def __init__(self, languages):self._languages = languages # 语言（dict,{文件后缀名：语言}）self._codelines = {suffix: (0, 0, 0) for suffix in languages} # 统计结果，{后缀名：(行数，大小，文件数)}self._successful = self._error = 0 # 记录成功、失败文件个数# @param directory: 要扫描的目录# @param log: 是否打印日志def scan(self, directory, log=False):if log: print('Scanning', directory)passdef report(self): # 输出结果passcounter = CodeLinesCounter(languages={'py': 'Python', 'c': 'C', 'cpp': 'C++', 'java': 'Java', 'js': 'JavaScript', 'html': 'HTML', 'css': 'CSS', 'txt': 'Plain text'}) # 创建CodeLinesCounter实例
counter.scan('E:/') # 扫描E盘（注意不能用'E:'）
counter.report() # 输出结果

完成，下面正式进入主要部分

2. 统计

2.1 文件扫描

首先，我们需要获取根目录下的文件列表。这可以用os.walk实现：
os.walk(rootdir)返回一个游走器（可迭代），包含根目录下每个子目录的文件及目录列表。我们来看一个例子：
有一文件夹Folder如下：

Folder
|   file1
|   Folder1
|       file2
|       file3
|   Folder2|   file4|   Folder3

运行如下代码：

import osfor root, dirs, files in os.walk('Folder'):print(root, dirs, files)

则输出如下：

Folder					['Folder1', 'Folder2']	['file1']
Folder\Folder1			[]						['file2', 'file3']
Folder\Folder2			['Folder3']				['file4']
Folder\Folder2\Folder3	[]						[]

其中第一项是当前的根目录，第二项为目录下的目录列表，第三项则为当前的文件列表。
因此，我们可以编写如下代码：

# -*- encoding: utf-8 -*-
from os.path import join, getsize, abspath
from os import walkclass CodeLinesCounter(object):SIZES = [('B', 1), ('KB', 1024), ('MB', 1024**2), ('GB', 1024**3), ('TB', 1024**4)]def __init__(self, languages):self._languages = languagesself._results = {suffix: (0, 0, 0) for suffix in languages}self._successful = self._error = 0def scan(self, directory, log=False):if log: print('Scanning', directory)try:for root, _, files in walk(abspath(directory)):for filename in files:suffix = filename[filename.rfind('.') + 1:]filename = join(root, filename)if suffix in self._results:lines, size, numFiles = self._results[suffix]lines += 1 # 暂不统计，先按一行计算numFiles += 1size += getsize(filename) # getsize返回文件大小（字节）self._results[suffix] = (lines, size, numFiles)if log: print(filename)except KeyboardInterrupt:print('\nUser stopped operation')else:if log: print('Scan finished')def report(self):print('Language\tLines\tSize\tFiles')for suffix, (lines, size, files) in sorted(self._results.items(), key=lambda x: x[1], reverse=True):print(self._languages[suffix], lines, self.__format_size(size), files, sep='\t')# 单位转换def __format_size(self, bytes):for suffix, size in self.SIZES:if bytes < size * 1024:return '%.2f %s' % (bytes / size, suffix)return '%.2f %s' % (bytes / self.SIZES[-1][1], 2, self.SIZES[-1][0])counter = CodeLinesCounter(languages={'py': 'Python', 'c': 'C', 'cpp': 'C++', 'java': 'Java', 'js': 'JavaScript', 'html': 'HTML', 'css': 'CSS', 'txt': 'Plain text'})
counter.scan('E:/')
counter.report()

运行结果应类似于下面这样（手动整理了一下）：

Language        Lines   Size    		Files
C++     		667     671.51 KB       667
Python  		317     981.01 KB       317
HTML    		38      466.52 KB       38
Plain text    34      90.69 KB        34
JavaScript    19      1.43 MB			19
CSS     		9       341.04 KB       9
C       		2       20.45 KB        2
Java    		1       676.00 B        1

好，下面来到行数统计部分（表格输出后面会介绍）。

2.2 行数统计

众所周知，空行不应该算在代码行数中。因此，统计时需忽略空行。先写上如下代码（替换掉刚才的23行）：

with open(filename, 'r', encoding='utf-8') as f: # utf-8编码打开文件for line in f:if line and not line.isspace(): # 去掉空行lines += 1

但是，正当我们兴致勃勃地运行时——

Traceback (most recent call last):...File "...\lib\codecs.py", line 322, in decode(result, consumed) = self._buffer_decode(data, self.errors, final)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xb5 in position 355: invalid start byte

程序报错UnicodeDecodeError，分析后发现原因是部分文件使用了GBK编码，而utf-8编码无法正确打开，因此造成错误。
我们再次改进程序，使其尝试两种编码：

try:ln = 0with open(filename, 'r', encoding='utf-8') as f:for line in f:if line and not line.isspace():ln += 1
except UnicodeDecodeError: # 尝试使用GBK编码打开try:ln = 0with open(filename, 'r', encoding='gbk') as f:for line in f:if line and not line.isspace():ln += 1except:print(filename, '[Error: unknown encoding]')self._error += 1else:lines += ln
except Exception as e:print(filename, '[Unknown error: %s]' % e)self._error += 1continue
lines += ln
if log: print(f'{filename} [{ln}]')
self._successful += 1

这次，我们得到了正确的结果：

Language        Lines   Size    		Files
C++     		35595   671.51 KB       667
JavaScript    24485   1.43 MB 		19
Python  		24130   982.16 KB       317
CSS     		8203    341.04 KB       9
HTML    		6138    466.52 KB       38
Plain text    741     90.69 KB        34
C       		557     20.45 KB        2
Java    		29      676.00 B        1

现在仅剩最后一步了——制表。

3. 制表

python输出表格可以使用PrettyTable库。具体用法如下：

# -*- encoding: utf-8 -*-
from os.path import join, getsize, abspath
from os import walk
from prettytable import PrettyTableclass CodeLinesCounter(object):SIZES = [('B', 1), ('KB', 1024), ('MB', 1024**2), ('GB', 1024**3), ('TB', 1024**4)]def __init__(self, languages):self._languages = languagesself._results = {suffix: (0, 0, 0) for suffix in languages}self._successful = self._error = 0def scan(self, directory, log=False):if log: print('Scanning', directory)try:for root, _, files in walk(abspath(directory)):for filename in files:suffix = filename[filename.rfind('.') + 1:]filename = join(root, filename)if suffix in self._results:lines, size, numFiles = self._results[suffix]numFiles += 1size += getsize(filename)try:ln = 0with open(filename, 'r', encoding='utf-8') as f:for line in f:if line and not line.isspace():ln += 1except UnicodeDecodeError: # Try 'gbk' encodingtry:ln = 0with open(filename, 'r', encoding='gbk') as f:for line in f:if line and not line.isspace():ln += 1except:print(filename, '[Error: unknown encoding]')self._error += 1else:lines += lnexcept Exception as e:print(filename, '[Unknown error: %s]' % e)self._error += 1continuelines += lnif log: print(f'{filename} [{ln}]')self._successful += 1self._results[suffix] = (lines, size, numFiles)elif log:print(filename, '[None]')except KeyboardInterrupt:print('\nUser stopped operation')else:if log: print('Scan finished')def report(self):table = PrettyTable(['Language', 'Lines', 'Size', 'Files'], title=f'Scan result (OK {self._successful}, Error {self._error})') # 创建PrettyTable实例，添加标题for suffix, (lines, size, files) in sorted(self._results.items(), key=lambda x: x[1], reverse=True):table.add_row([self._languages[suffix], lines, self.__format_size(size), files]) # 添加行print(table) # 输出def __format_size(self, bytes):for suffix, size in self.SIZES:if bytes < size * 1024:return '%.2f %s' % (bytes / size, suffix)return '%.2f %s' % (bytes / self.SIZES[-1][1], 2, self.SIZES[-1][0])counter = CodeLinesCounter(languages={'py': 'Python', 'c': 'C', 'cpp': 'C++', 'java': 'Java', 'js': 'JavaScript', 'html': 'HTML', 'css': 'CSS', 'txt': 'Plain text'})
counter.scan('E:/')
counter.report()

运行结果：

+----------------------------------------+
|     Scan result (OK 1087, Error 0)     |
+------------+-------+-----------+-------+
|  Language  | Lines |    Size   | Files |
+------------+-------+-----------+-------+
|    C++     | 35595 | 671.51 KB |  667  |
| JavaScript | 24485 |  1.43 MB  |   19  |
|   Python   | 24130 | 982.16 KB |  317  |
|    CSS     |  8203 | 341.04 KB |   9   |
|    HTML    |  6138 | 466.52 KB |   38  |
| Plain text |  741  |  90.69 KB |   34  |
|     C      |  557  |  20.45 KB |   2   |
|    Java    |   29  |  676.00 B |   1   |
+------------+-------+-----------+-------+

4. 总结

最终代码（无注释）：

# -*- encoding: utf-8 -*-
from os.path import join, getsize, abspath
from os import walk
from prettytable import PrettyTableclass CodeLinesCounter(object):SIZES = [('B', 1), ('KB', 1024), ('MB', 1024**2), ('GB', 1024**3), ('TB', 1024**4)]def __init__(self, languages):self._languages = languagesself._results = {suffix: (0, 0, 0) for suffix in languages}self._successful = self._error = 0def scan(self, directory, log=False):if log: print('Scanning', directory)try:for root, _, files in walk(abspath(directory)):for filename in files:suffix = filename[filename.rfind('.') + 1:]filename = join(root, filename)if suffix in self._results:lines, size, numFiles = self._results[suffix]numFiles += 1size += getsize(filename)try:ln = 0with open(filename, 'r', encoding='utf-8') as f:for line in f:if line and not line.isspace():ln += 1except UnicodeDecodeError: # Try 'gbk' encodingtry:ln = 0with open(filename, 'r', encoding='gbk') as f:for line in f:if line and not line.isspace():ln += 1except:print(filename, '[Error: unknown encoding]')self._error += 1else:lines += lnexcept Exception as e:print(filename, '[Unknown error: %s]' % e)self._error += 1continuelines += lnif log: print(f'{filename} [{ln}]')self._successful += 1self._results[suffix] = (lines, size, numFiles)elif log:print(filename, '[None]')except KeyboardInterrupt:print('\nUser stopped operation')else:if log: print('Scan finished')def report(self):table = PrettyTable(['Language', 'Lines', 'Size', 'Files'], title=f'Scan result (OK {self._successful}, Error {self._error})')for suffix, (lines, size, files) in sorted(self._results.items(), key=lambda x: x[1], reverse=True):table.add_row([self._languages[suffix], lines, self.__format_size(size), files])print(table)def __format_size(self, bytes):for suffix, size in self.SIZES:if bytes < size * 1024:return '%.2f %s' % (bytes / size, suffix)return '%.2f %s' % (bytes / self.SIZES[-1][1], 2, self.SIZES[-1][0])counter = CodeLinesCounter(languages={'py': 'Python', 'c': 'C', 'cpp': 'C++', 'java': 'Java', 'js': 'JavaScript', 'html': 'HTML', 'css': 'CSS', 'txt': 'Plain text'})
counter.scan('E:/')
counter.report()

后期改进：

• 增加正则表达式忽略文件
• matplotlib绘图
• PyQt5GUI
• ……（欢迎提出宝贵的意见！）