PDB set trace

PDB (Python Debugger) is a powerful tool that allows developers to debug their Python code by stepping through the code and inspecting variables. The pdb set trace command is a commonly used feature of PDB that sets a breakpoint at the current location in the code and drops you into the debugger.

Usage

To use pdb set trace, you first need to import the pdb package into your code.

import pdb

Next, you can add the pdb.set_trace() command at any point in your code where you want to set a breakpoint. For example:

def my_function():
    x = 1
    y = 2
    pdb.set_trace()
    z = x + y
    return z

When the pdb.set_trace() command is executed, the code will stop at that point and you will be able to step through the code using various PDB commands.

PDB Commands

Once you are in the PDB debugger, you can use various commands to step through your code and inspect variables.

• n - Execute the next line of code
• s - Step into a function call
• c - Continue execution until a breakpoint is encountered
• q - Quit the debugger
• p - Print the value of a variable
• l - List the current line of code and surrounding lines
• h - List all available PDB commands and their descriptions

These commands can be combined with various arguments to provide more detailed information. For example, p x would print the value of the variable x.

Conclusion

PDB set trace is a powerful debugging tool that can help you quickly find and fix bugs in your Python code. By setting breakpoints and stepping through your code, you can gain deeper insight into how your program is executing and identify areas that need improvement.