King of Python debugger @pysnooper
Contents
PySnooper
@pysnooper 是一個非常好用的裝飾器，當你在使用 print 或是 IDE 斷點 debug 時候，往往需要設置斷點或是許多 print 才能發現問題所在。
@pysnooper 可以幫你用知道哪些正在運行、哪些函數被使用，只需將裝飾器放置於 function 中，將會得到所有的步驟，包含使用哪些動作、函數與時間。
The best way to install @pysnooper is with Pip
pip install PySnooper
Example
This function that converts a number to binary，讓我們來利用 @pysnooper.snoop() 裝飾器來跟蹤此 function 的所有事情吧！
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)
Output：
Source path:... <stdin>
Starting var:.. number = 6
22:58:09.555171 call 1 SOURCE IS UNAVAILABLE
22:58:09.555982 line 3 SOURCE IS UNAVAILABLE
22:58:09.556162 line 4 SOURCE IS UNAVAILABLE
New var:....... bits = []
22:58:09.556287 line 5 SOURCE IS UNAVAILABLE
22:58:09.556463 line 6 SOURCE IS UNAVAILABLE
Modified var:.. number = 3
New var:....... remainder = 0
22:58:09.556575 line 7 SOURCE IS UNAVAILABLE
Modified var:.. bits = [0]
22:58:09.556801 line 5 SOURCE IS UNAVAILABLE
22:58:09.556950 line 6 SOURCE IS UNAVAILABLE
Modified var:.. number = 1
Modified var:.. remainder = 1
22:58:09.557837 line 7 SOURCE IS UNAVAILABLE
Modified var:.. bits = [1, 0]
22:58:09.558126 line 5 SOURCE IS UNAVAILABLE
22:58:09.558334 line 6 SOURCE IS UNAVAILABLE
Modified var:.. number = 0
22:58:09.558496 line 7 SOURCE IS UNAVAILABLE
Modified var:.. bits = [1, 1, 0]
22:58:09.558692 line 5 SOURCE IS UNAVAILABLE
22:58:09.558882 line 8 SOURCE IS UNAVAILABLE
22:58:09.570057 return 8 SOURCE IS UNAVAILABLE
Return value:.. [1, 1, 0]
Elapsed time: 00:00:00.015191
[1, 1, 0]
Output to the file:
@pysnooper.snoop('/log/file.log')