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Python Write Better Python Buggy Logs The Python Debugger

Posted by Eugene Yan
Eugene Yan
3,896 Points

Hello, i have tried to run PDB in my code in Wing IDE; and every time I run the code, an exception occurs.

My code is something like this: import pdb pdb.set_trace()

def test(what): if what == 0: return 0 print('dream lvl: {}'.format(what)) recur = rec(what-1)

test(10)

and this shows up: Cannot read termcap database; using dumb terminal settings. Traceback (most recent call last): File "/Applications/Wing101.app/Contents/Resources/src/debug/tserver/sandbox.py", line 2, in <module> if __name_ == 'main': File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/pdb.py", line 1579, in set_trace Pdb().set_trace(sys._getframe().f_back) File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/bdb.py", line 251, in set_trace sys.settrace(self.trace_dispatch) File "/Applications/Wing101.app/Contents/Resources/bin/3.4/src/debug/tserver/dbgserver.py", line 624, in _SysSetTraceReplacement builtins.RuntimeError: WARNING: sys.settrace(<bound method Pdb.trace_dispatch of <pdb.Pdb object at 0x102676048>>) called: This breaks some debugger functionality. Use 'Ignore this exception location' in the Exceptions tool and restart debugging to suppress this warning

The code works fine if I don't import pdb and call the set_trace function.

Eugene Yan
Eugene Yan
3,896 Points

code:

import pdb

pdb.set_trace()

def test(what):

if what == 0:

    return 0

print('dream lvl: {}'.format(what))

recur = rec(what-1)

test(10)

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,423 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

In running your code, I get the error NameError: name 'rec' is not defined due to the line recur = rec(what-1). Did you mean to say:

recur = test(what-1)

Also, you might want to move the call to the pdb.set_trace() to precisely where it should begin. For example, if placed as the first line within the test() function code block:

import pdb

def test(what):
        pdb.set_trace()  # <-- new location
        if what == 0:                
                return 0
        print('dream lvl: {}'.format(what))
        recur = test(what-1)  # <-- rename 'rec' to 'test'

# call test function
test(10)

In ipython this would look like:

In [28]: def test(what):
            pdb.set_trace()  # <-- new location
            if what == 0:                
                        return 0
            print('dream lvl: {}'.format(what))
            recur = test(what-1)  # <-- rename 'rec' to 'test'
   ....:     

In [29]: test(10)
> <ipython-input-28-d012234bbc40>(3)test()
-> if what == 0:
(Pdb) cont
dream lvl: 10
> <ipython-input-28-d012234bbc40>(3)test()
-> if what == 0:
(Pdb) cont
dream lvl: 9
> <ipython-input-28-d012234bbc40>(3)test()
-> if what == 0:
(Pdb) cont
dream lvl: 8
> <ipython-input-28-d012234bbc40>(3)test()
-> if what == 0:
(Pdb) cont
dream lvl: 7
> <ipython-input-28-d012234bbc40>(3)test()
-> if what == 0:
(Pdb) cont
dream lvl: 6
> <ipython-input-28-d012234bbc40>(3)test()
-> if what == 0:
(Pdb) cont
dream lvl: 5
> <ipython-input-28-d012234bbc40>(3)test()
-> if what == 0:
(Pdb) cont
dream lvl: 4
> <ipython-input-28-d012234bbc40>(3)test()
-> if what == 0:
(Pdb) cont
dream lvl: 3
> <ipython-input-28-d012234bbc40>(3)test()
-> if what == 0:
(Pdb) cont
dream lvl: 2
> <ipython-input-28-d012234bbc40>(3)test()
-> if what == 0:
(Pdb) cont
dream lvl: 1
> <ipython-input-28-d012234bbc40>(3)test()
-> if what == 0:
(Pdb) cont

In [30]:

To help make your code examples easier to read, you might want to include triple-quotes as seen in the Markdown Cheatsheet.