Python uses IPython to improve development efficiency

1. Introduction to IPython

IPython is an interactive Python interpreter, and it is more efficient.

The difference between it and most traditional working modes (Edit-> Compile-> Run) is that the working mode it adopts is:Execution-> Exploration, and most codes related to data analysis contain exploratory operations (such as trial and error methods and iteration methods), so IPython can greatly improve coding efficiency.

IPython has developed to this point. It is not just an enhanced version of the Python shell.

It integrates a GUI console

, which allows you to directly perform drawing operations; It also There is a web-based interactive notebook and a lightweight fast parallel computing engine.

2. Write codeEnter ipython in Terminal to start IPython.

If you need to use the Matplotlib library, you need to mark the integration of the Matplotlib package at startup, then change the startup command to: ipython --pylab

1. Learn to use the Tab key

When entering code, if this is a content that has been entered before (such as a variable defined earlier), you only need to press the Tab key after entering the first few letters to automatically complete it.

IPython having this feature is a major improvement over the standard Python shell, which is already very common in IDEs for other languages.

Not only can it automatically complete variables, objects, etc., but the Tab key can also automatically complete file paths just like typing commands in Terminal.

2. Use the up and down arrow keys to quickly enter historical commands

When a command or code needs to be entered repeatedly, you don’t have to type it manually every time, just Use the up arrow key to automatically complete the previous command; continue to press the up arrow key at this time to complete the previous command.

If a command requires pressing the up arrow key many times to find it, you only need to enter the first few letters of the command and then press the up arrow key to filter only the first few letters. letter command.

3. Execute a .py file

If you want to execute an external .py file, use the %run command, for example:

4. View general information about related code

When you need to view general information about a variable or object, add a question mark after the variable Then press the Enter key. For example:

If a function contains a docstring, add a question mark (?) after the function name to view the relevant docstring content;

If in the function Add two question marks (??) after the name to display the source code related to the function, for example:

5. Relevant shortcut keys during the coding process

Ctrl+F Move the cursor forward 1 character

Ctrl+B Move the cursor back 1 character

Ctrl+ A Move the cursor to the beginning of the line

Ctrl+E Move the cursor to the end of the line

Ctrl+U Delete everything before the cursor on this line

Ctrl+K deletes all content after the cursor on this line

Ctrl+L clears the screen (Cmd+K can also be used on Mac)

3. Debugging code

1. Start the debugger after an exception occurs in the code

After an exception occurs in the code, enter the %debug command to start the debugger and Automatically jump to the "location of the incident":

Enter the q command to exit the debugger.

2. Single-step execution

Use the %run command with the -d option to open the debugger in advance, enter s to step into the function call, enter The n command is executed to the next line of code. Enter an exclamation point (!) followed by the variable name to view the value of the variable. For example:

If you add an option (-b) specifying the line number to this command, you can set a breakpoint when starting the debugger, for example:

For more articles related to Python using IPython to improve development efficiency, please pay attention to the PHP Chinese website!