Pycharm Code Editor

PyCharm Code Editor

PyCharm, as a professional Python IDE, offers powerful code editing features.

Core Features of Code Editing

This section will introduce the core functions of code editing, including intelligent completion, shortcut operations, and code refactoring—efficient development techniques.

Basic Editing Features

Code Completion

Completion Type	Trigger Method	Description
Basic Completion	Ctrl + Space (Win/Linux), ⌘ + Space (Mac)	Displays suggestions for variables, functions, classes, etc.
Smart Type Completion	Ctrl + Shift + Space	Recommends more precise types based on context.
File Name Completion	Automatically triggered when entering a path	Quickly completes file paths.
Dynamic Template Completion	Enter an abbreviation (e.g., main + Tab)	Quickly generates code snippets (e.g., if __name__ ==...).

Input im + Tab → Automatically completes to import:

Input for + Tab → Generates a complete for loop structure:

Syntax Highlighting

PyCharm automatically colors code elements:

Keywords (def, class): Blue
Strings: Green
Comments: Gray
Incorrect Syntax: Red wavy line

Customizing Highlighting:

Go to Settings → Editor → Color Scheme
Adjust the colors for Python syntax elements

Code Folding

Action	Shortcut (Win/Linux)	Shortcut (Mac)
Fold Current Block	Ctrl + -	⌘ + -
Unfold Current Block	Ctrl + +	⌘ + +
Fold All Blocks	Ctrl + Shift + -	⌘ + Shift + -
Unfold All Blocks	Ctrl + Shift + +	⌘ + Shift + +

Hover over the left side of the editor area to see a downward arrow; clicking it also folds the code.

Supported Code Structures for Folding:

Functions/Methods
Class Definitions
Multiline Comments
Import Statement Groups

Shortcuts and Efficient Operations

Function	Shortcut (Win/Linux)	Shortcut (Mac)
Copy Current Line	Ctrl + D	⌘ + D
Delete Current Line	Ctrl + Y	⌘ + Delete
Move Line	Alt + Shift + ↑/↓	⌥ + ⇧ + ↑/↓
Quick Fix Suggestions	Alt + Enter	⌥ + Enter
Jump to Definition	Ctrl + B	⌘ + B
View Parameter Hints	Ctrl + P	⌘ + P

Multi-Line Editing and Batch Operations

Column Selection Mode

1. Hold down Alt (Win) or ⌥ (Mac) while dragging with the mouse.

2. Alternatively, use Alt + Shift + Insert to switch to column mode.

Application Scenarios:

Bulk modification of variable prefixes: old_name = 1 → new_name = 1, old_value = 2 → new_value = 2

Multi-Cursor Editing

1. Hold down Alt and click with the mouse (to add multiple cursors).

2. Or press Ctrl + G (Win) / ⌘ + G (Mac) to select identical words.

Code Formatting and Refactoring

Automatic Code Formatting

1. **Format Current File**:

Press Ctrl + Alt + L (Win/Linux)
Press ⌥ + ⌘ + L (Mac)

2. **Format Selected Code**:

Select the code → Right-click → Reformat Code

Configuring Formatting Rules:

Go to Settings → Editor → Code Style → Python

Rename Variables/Functions (Safe Refactoring)

1. Select the identifier (variable/function name).

2. Right-click → Refactor → Rename

3. Or use the shortcut Shift + F6

4. Enter the new name → Press Enter

Effect:

All references to this identifier are updated simultaneously.
Supports renaming across files.

Extract Method

Extract a selected code snippet into a new method:

Select the code block.
Press Ctrl + Alt + M (Win) / ⌘ + ⌥ + M (Mac).
Enter the method name → Confirm.

Example:

    # Before Extraction
    def process_data(data):
        cleaned = []
        for item in data:
            if item.is_valid():
                cleaned.append(item)
        return cleaned

    # After Extraction
    def process_data(data):
        cleaned = []
        for item in data:
            if is_valid_item(item):
                cleaned.append(item)
        return cleaned

    def is_valid_item(item):
        return item.is_valid()

Inline

Inline a method or variable into its call site:

Place the cursor at the method name or variable.
Press Ctrl + Alt + N (Win) / ⌘ + ⌥ + N (Mac).

Before Inline:

    def calculate_discount(price):
        return price * 0.9
    total = calculate_discount(100)

After Inline:

    total = 100 * 0.9

Advanced Editing Techniques

Live Templates

Quickly generate commonly used code patterns:

Enter an abbreviation (e.g., iter) → Press Tab
Preset templates:

main → Generates if __name__ == '__main__'
try → Generates a complete try-except block

Customizing Templates:

Go to Settings → Editor → Live Templates

In the code editor, typing "iter" displays template information:

Code Intent Actions (Alt+Enter)

Quickly fix or optimize code based on context:

Automatically import missing packages
Convert string formats (f-string / format)
Optimize conditional expressions

Operation: Place the cursor on a warning or suggestion → Press Alt + Enter

Summary: Efficient Editing Workflow

Writing Phase:

Use code completion (`Ctrl + Space`) for quick input
Use dynamic templates to generate repetitive structures

Optimization Phase:

Format code (`Ctrl + Alt + L`)
Use `Alt + Enter` to quickly fix issues

Refactoring Phase:

Extract methods (`Ctrl + Alt + M`)
Perform safe renames (`Shift + F6`)

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