debugging.md

Debugging

Use the help() function to view documentation for a given object or datatype:

help(str)

Use the dir() function to see what methods you can call on a given object.

dir("Hello")

Interactive Console

As of a recent version of Python, you should be able to use the built-in breakpoint() function to drop an interactive breakpoint on any line of code. Once you run the script, it will stop at the breakpoint to facilitate further investigation:

v = 1

breakpoint()

v = 2

#> (Pdb) v
#> 1
#> (Pdb)

for i in [1, 2, 3, 4, 5]:
    print(i)
    if i == 4:
        breakpoint()

#> 1
#> 2
#> 3
#> 4
#> > /Users/mjr/Desktop/my_script.py(3)<module>()
#> -> for i in [1, 2, 3, 4, 5]:
#> (Pdb) i
#> 4
#> (Pdb)

Various modules and third-party packages offer alternative or equivalent interactive debugging capabilities:

• code
• pdb
• ipython