Python模块之pysnooper

一、简介

调试程序时，很多人喜欢直接用print来代替断点调试，而pysnooper模块比print更方便，以装饰器的形式存在

二、实验环境

　　操作系统：win10

　　python版本：python3.6

三、安装pysnooper模块

　　pip3 install pysnooper

四、简单实例

　　需求：屏幕打印每个变量的值

import pysnooper

@pysnooper.snoop()
def test():
    a = 100*1
    sum=0
    for i in range(10):
        sum +=i
    sum2 = sum +a
    return sum2

if __name__ == '__main__':
    test()

　　结果输出：

17:07:38.982924 call         4 def test():
17:07:38.982924 line         5     a = 100*1
New var:....... a = 100
17:07:38.982924 line         6     sum=0
New var:....... sum = 0
17:07:38.982924 line         7     for i in range(10):
New var:....... i = 0
17:07:38.982924 line         8         sum +=i
17:07:38.982924 line         7     for i in range(10):
Modified var:.. i = 1
17:07:38.982924 line         8         sum +=i
Modified var:.. sum = 1
17:07:38.983889 line         7     for i in range(10):
Modified var:.. i = 2
17:07:38.983889 line         8         sum +=i
Modified var:.. sum = 3
17:07:38.983889 line         7     for i in range(10):
Modified var:.. i = 3
17:07:38.983889 line         8         sum +=i
Modified var:.. sum = 6
17:07:38.983889 line         7     for i in range(10):
Modified var:.. i = 4
17:07:38.983889 line         8         sum +=i
Modified var:.. sum = 10
17:07:38.983889 line         7     for i in range(10):
Modified var:.. i = 5
17:07:38.983889 line         8         sum +=i
Modified var:.. sum = 15
17:07:38.983889 line         7     for i in range(10):
Modified var:.. i = 6
17:07:38.983889 line         8         sum +=i
Modified var:.. sum = 21
17:07:38.983889 line         7     for i in range(10):
Modified var:.. i = 7
17:07:38.983889 line         8         sum +=i
Modified var:.. sum = 28
17:07:38.983889 line         7     for i in range(10):
Modified var:.. i = 8
17:07:38.983889 line         8         sum +=i
Modified var:.. sum = 36
17:07:38.983889 line         7     for i in range(10):
Modified var:.. i = 9
17:07:38.983889 line         8         sum +=i
Modified var:.. sum = 45
17:07:38.983889 line         7     for i in range(10):
17:07:38.983889 line         9     sum2 = sum +a
New var:....... sum2 = 145
17:07:38.983889 line        10     return sum2
17:07:38.983889 return      10     return sum2
Return value:.. 145

结果

五、pysnooper.snoop传参介绍

output='a.txt'        #将结果保存到文件a.txt
variables=('a')     #打印非局部变量a的值
depth=1             #Show snoop lines for functions that your function calls
prefix='hello'      #在每一行打印信息前添加hello