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Debugging

pdb⚑

Since Python 3.7, we can just call breakpoint() and this will import pdb (or the debugger defined in the environment variable PYTHONBREAKPOINT) and set the breakpoint in that part of the code. This will stop the program execution once the breakpoint is reached. Then, an interactive console while appear.

Usage⚑

The main commands are:

  • args: Print the argument list of the current function.
  • break: Creates a breakpoint (requires parameters) in the program execution.
  • continue: Continues program execution.
  • help: Provides list of commands or help for a specified command.
  • jump: Set the next line to be executed
  • list: Print the source code around the current line.
  • next: Continue execution until the next line in the current function is reached or returns.
  • step: Execute the current line, stopping at first possible occasion.
  • pp: Pretty-prints the value of the expression.
  • quit: Aborts the program.
  • return: Continue execution until the current function returns.

All of the above commands (except for pp) can be called by only its first letter (e.g., continue -> c).

Misc⚑

Obkect details⚑

See a function definition at runtime⚑
from somewhere import somefunction
from inspect import getsource

print(getsource(somefunction))

Get function signature at runtime⚑

from somewhere import somefunction
from inspect import signature

print(signature(somefunction))

References⚑

better-exceptions⚑

Pretty and more helpful exceptions in Python, automatically.

pip install better_exceptions
export BETTER_EXCEPTIONS=1