项目地址

https://github.com/cool-RR/pysnooper

安装

pip install pysnooper

使用举例

跟踪整个函数

用例: 编写一个函数，它通过返回一个位列表来将一个数转换成二进制。通过加@pysnooper.snoop() 装饰器,来举例pysnooper的使用方法.

#!/usr/bin/env python
# coding=utf-8
# author: wz
# mail: 277215243@qq.com
# datetime:2019/5/10 5:31 PM
# web: https://www.bthlt.com
import pysnooper

@pysnooper.snoop()
def number_to_bits(number):
    if number:
        bits = []
        while number:
            number, remainder = divmod(number, 2)
            bits.insert(0, remainder)
        return bits
    else:
        return [0]

number_to_bits(6)

输出:

Starting var:.. number = 6
17:31:48.186679 call         9 def number_to_bits(number):
17:31:48.186884 line        10     if number:
17:31:48.186913 line        11         bits = []
New var:....... bits = []
17:31:48.186950 line        12         while number:
17:31:48.186973 line        13             number, remainder = divmod(number, 2)
New var:....... remainder = 0
Modified var:.. number = 3
17:31:48.187016 line        14             bits.insert(0, remainder)
Modified var:.. bits = [0]
17:31:48.187051 line        12         while number:
17:31:48.187076 line        13             number, remainder = divmod(number, 2)
Modified var:.. number = 1
Modified var:.. remainder = 1
17:31:48.187118 line        14             bits.insert(0, remainder)
Modified var:.. bits = [1, 0]
17:31:48.187151 line        12         while number:
17:31:48.187175 line        13             number, remainder = divmod(number, 2)
Modified var:.. number = 0
17:31:48.187208 line        14             bits.insert(0, remainder)
Modified var:.. bits = [1, 1, 0]
17:31:48.187242 line        12         while number:
17:31:48.187265 line        15         return bits
17:31:48.187290 return      15         return bits
Return value:.. [1, 1, 0]

跟踪部分函数

用例:如果不想跟踪整个函数，可以将相关的部分打包成块：

#!/usr/bin/env python
# coding=utf-8
# author: wz
# mail: 277215243@qq.com
# datetime:2019/5/10 5:31 PM
# web: https://www.bthlt.com
import pysnooper
import random

def foo():
    lst = []
    for i in range(10):
        lst.append(random.randrange(1, 1000))

    with pysnooper.snoop():
        lower = min(lst)
        upper = max(lst)
        mid = (lower + upper) / 2
        print(lower, mid, upper)

foo()

输出:

New var:....... i = 9
117 535.5 954
New var:....... lst = [622, 795, 946, 518, 954, 848, 117, 480, 292, 885]
17:46:48.497081 line        16         lower = min(lst)
New var:....... lower = 117
17:46:48.497306 line        17         upper = max(lst)
New var:....... upper = 954
17:46:48.497350 line        18         mid = (lower + upper) / 2
New var:....... mid = 535.5
17:46:48.497684 line        19         print(lower, mid, upper)

其他特性

如果不方便访问stderr，则可以重定向到文件：

@pysnooper.snoop('/my/log/file.log')

查看非局部变量的值：

@pysnooper.snoop(variables=('foo.bar', 'self.whatever'))

显示函数调用的snoop行：

@pysnooper.snoop(depth=2)

窥探指定前缀的行：

@pysnooper.snoop（prefix ='ZZZ'）

葫芦的运维日志

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