SoFunction
Updated on 2025-04-09

Implementation of python breakpoint testing

In Python, breakpoint testing is a very useful debugging technique that can help you pause program execution, check the value of variables, the status of the program, etc. Here are several common methods for performing Python breakpoint testing:

1. Use print statements (simple but not very convenient)

This is the most basic debugging method. You can insert some in the codeprintStatements to output variable values ​​or some key program status information.

def add_numbers(a, b):
    print("Before addition, a =", a, "b =", b)
    result = a + b
    print("After addition, result =", result)
    return result
add_numbers(3, 5)

In this simple function,printThe statement can see the values ​​of the variables before and after the addition operation. However, this method has some disadvantages, such as if the program to be debugged is more complicated and needs to be added and deleted frequentlyprintstatements, and the output information may be messy.

2. Use the built-in pdb module in Python

  • Basic usage method

pdbIt is a standard debugging module for Python. You can insert it in the codepdb.set_trace()Statement to set breakpoints.

For example:

   import pdb

   def divide_numbers(a, b):
       pdb.set_trace()
       result = a / b
       return result
   divide_numbers(6, 2)

When the program executespdb.set_trace()When this line, the program will pause and enterpdbDebug mode. At this point, you will see a(Pdb)Prompt, here you can enter various debug commands.

Commonly used pdb debugging commands

  • n(next): Execute the next line of code. If the next line is a function call, it executes the entire function and then stops on the next line after the function call.
  • s(step): Execute the next line of code. If the next line is a function call, it will enter the function inside and stop at the first line inside the function.
  • c (continue): Continue to execute the program until the next breakpoint is encountered or the program ends.
  • l(list): List the code around the current line, the default is 11 lines.
  • p(print): Print the value of the variable. For example,p aWill print variablesavalue.

Start pdb debugging in the command line

You can also start directly from the command linepdbTo debug a Python script. Suppose your script is named, you can use the following command:

python -m pdb

This way the program will be executed from the first line, and you can use it when it is executed to each linepdbdebug commands to control program execution.

3. Use the debugging function of the integrated development environment (IDE) (recommended)

Debugging in PyCharm

  • In PyCharm, you can set a breakpoint by clicking on the blank area next to the line number of the code (a red dot will appear).
  • You can then start debugging by clicking the debug button (usually a green bug icon).
  • When the program executes to a breakpoint, execution will be paused. You can view the value of the variable, execution steps and other information in the debug window. You can also use functions such as single step execution (F8), entry function (F7), and jump out function (Shift + F8) to control the debugging process of the program.

Debugging in VS Code

In VS Code, you need to create a debug configuration file first (.vscode/). It can be created by clicking the gear icon in the debug panel.

A simple example of a configuration file is as follows:

   {
       "version": "0.2.0",
       "configurations": [
           {
               "name": "Python: Current File",
               "type": "python",
               "request": "launch",
               "program": "${file}",
               "console": "integratedTerminal"
           }
       ]
   }

After setting up the configuration file, you can click next to the code line number to set the breakpoint. Then click the debug button (a bug icon next to a green triangle) to start debugging. During the debugging process, you can view the value of the variable, call stack and other information, and you can use single steps to perform operations.

This is the end of this article about the implementation of python breakpoint testing. For more related python breakpoint testing content, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!