What is the breakpoint function for

Question

I’m digging myself in python, and as a good curious beginner I am researching the functions already present in the python without the use of any library, when I come across the function breakpoint(). I don’t really understand what its function is in itself, since the language of the official website is very formal and I still don’t have the wit to understand some terms...

Answer 1

The built-in function breakpoint() calls the Python Interactive Source Code Debugger.
This debugger features:

• Support the definition of conditional and single-pass interruption points at source.
• Inspection of stack frame.
• Source code listing.
• Arbitrary Python code evaluation in the context of any stack frame.

Running the example:

a = "teste"
breakpoint()
print(a)

When the interpreter finds the function breakpoint() command line will switch to the shell of the interactive Python source debugger (Pdb)

> /home/runner/2608v0dh5c5/main.py(3)<module>()
-> print(a)
(Pdb) ▉

To know the list of available commands type on this command line h or help:

> /home/runner/2608v0dh5c5/main.py(3)<module>()
-> print(a)
(Pdb) help

Documented commands (type help <topic>):
========================================
EOF    c          d        h         list      q        rv       undisplay
a      cl         debug    help      ll        quit     s        unt      
alias  clear      disable  ignore    longlist  r        source   until    
args   commands   display  interact  n         restart  step     up       
b      condition  down     j         next      return   tbreak   w        
break  cont       enable   jump      p         retval   u        whatis   
bt     continue   exit     l         pp        run      unalias  where    

Miscellaneous help topics:
==========================
exec  pdb

(Pdb) ▉

To get a description of a specific command type help <nome_do_comando>:

(Pdb) help next
n(ext)
        Continue execution until the next line in the current function
        is reached or it returns.
(Pdb) ▉

The elementary commands are:

• p expressão : Evaluates the expression expression in the current context and prints its value. Example:

(Pdb) p a
'teste'
(Pdb) ▉

• whatis expressão : Displays the type of expressão. Example:

(Pdb) whatis a
<class 'str'>
(Pdb) ▉

• !declaração : Executes a declaração of a line. Example:

(Pdb) !a = "não é mais um teste"
(Pdb) p a
'não é mais um teste'
(Pdb) ▉

• next : Continue execution until the next line in the current function is reached or it returns. Example:

(Pdb) next
não é mais um teste
--Return--
> /home/runner/2608v0dh5c5/main.py(3)<module>()->None
-> print(a)
(Pdb) ▉

A full description of the commands available in the Python interactive source debugger is available in the online documentation.