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Python Indent

Correct Python indentation in Visual Studio Code. See the extension on the VSCode Marketplace and its source code on GitHub.

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How it works

When you press Enter, your Python code is parsed up to the cursor in order to find the correct indentation level of nearby lines. Because the "correct" indentation level can be an arbitrary number of spaces, the use of tabs (\t) is not supported.

For more detailed explanation of the behavior, see the section "Detailed Behavior" below.

Settings

There are three exposed settings.

  • pythonIndent.useTabOnHangingIndent
  • pythonIndent.useTabOnHangingIndent
    • boolean, the default is false
    • If true, after creating a hanging indent (see footnote 1 of PEP8 for a definition of a hanging indent), you can use the tab key to leave the indented section and go to the ending bracket.
  • pythonIndent.trimLinesWithOnlyWhitespace
    • boolean, the default is false
    • If true, trims lines that contain only whitespace after pressing Enter on them. This behavior is similar to VS Code's default.
  • pythonIndent.keepHangingBracketOnLine
    • boolean, the default is false
    • If true, when creating a hanging indent, do not put the closing bracket on its own line.

Release notes

See the change log.

Detailed behavior

There are three main cases when determining the correct indentation, described below.

Between bracket pairs

In cases when you have your cursor between an open bracket (one of [({) and its closing bracket pair (the corresponding one of })]), this extension will keep subsequent lines indented just to the right of where it was opened:

data = {'a': 0,
        | # <- pressing enter should put your cursor at the "|"
| # <- this is where default VS Code puts your cursor

Even heavily nested brackets are handled:

data = {'a': 0,
        'b': [[1, 2],
              | # <- match the more recently opened [ instead of the {
        | # <- default behavior of VS Code
data = {'a': 0,
        'b': [[1, 2],
              [3, 4]],
        | # <- since the lists are all closed, go back to the { position
              | # <- default behavior of VS Code
data = {'a': 0,
        'b': [[1, 2],
              [3, 4]],
        'c': 5}
| # <- go back to indentation level before any brackets were opened
        | # <- default behavior of VS Code

In the full example below, default VS Code required nine extra key presses (three tabs, two spaces, and four backspaces) to match the automatic indentation of this extension.

data = {'a': 0,
        'b': [[1, 2],
              [3, 4]],
        'c': 5}
done(data)

Hanging indents

When you have opened a bracket, but not yet inserted any content, pressing Enter will create a hanging indent, matching the base behavior of VS Code.

result = my_func(
    | # <- your cursor should end up here
) # <- the closing bracket should end up here

You can use the setting useTabOnHangingIndent to make it so that when you are done typing you can simply press Tab to be taken to the closing bracket.

If there is content to the right of your cursor when you press Enter, then this extension falls back on just indenting by your set tab size.

# The "|" is your cursor's location
result = my_func(|x, y, z)
# and when you press Enter...
result = my_func(
    |x, y, z)

If you never want to have the closing bracket end up on its own line (i.e. you always want to just indent by the set tab size), use the keepHangingBracketOnLine configuration setting. Warning: This may cause confusing indentation with function definitions as the argument list and the function code may end up at the same indentation level.

It's not often used, but a backslash to continue a line will also result in the next line being indented.

my_long_calculation = 1234 + \
    5678

Keywords

Some keywords in Python imply certain indentation behaviors. For example, if there is a return statement, then we know the next line can be un-indented (or dedented) since no statements can follow a return in the same code block. Other keywords that follow the same pattern are pass, break, continue, and raise.

Similarly, if there is an else: on the current line, then the current line needs to be dedented, and the next line needs to be indented relative to the new position of the else:. Other keywords that follow the same pattern are elif ...:, except ...:, and finally:. Some examples are shown below.

if True:
    pass
    else:|
# and when you press Enter...
if True:
    pass
else:
    |

But if you have manually changed the indentation, the extension should not change it for you:

if True:
    if True:
        pass
    else:|
# and when you press Enter, do NOT dedent!
if True:
    if True:
        pass
    else:
        |

# Or even more nested
if True:
    if True:
        if True:
            pass
    else:|
# and when you press Enter, still do NOT dedent
if True:
    if True:
        if True:
            pass
    else:
        |

Extending comments

If (and only if) you press Enter while your cursor is in the middle of a comment, then the next line will automatically be made into a comment.

# As always, the "|" indicates your cursor
def f():
    # This function is |gonna be REAL good!

def f():
    # This function is
    # |gonna be REAL good

Trimming whitespace lines

You can trim whitespace from lines that contain only whitespace by using the trimLinesWithOnlyWhitespace configuration setting (the default is to not trim whitespace in this way). This setting brings the behavior closer to native VSCode behavior.

# In the below code, the character "·" represents a space
def f():
····|

# The default of false preserves whitespace
def f():
····
····|

# Setting trimLinesWithOnlyWhitespace = true will trim the whitespace
def f():

····|

Developing

See the developer docs for pointers on how to develop this extension.

Why is it needed?

This style of indentation has not been prioritized for support by the vscode-python team, and it's unclear if it ever will be.

See some related issues: [1], [2], [3], [4], [5]

Caveats

Known caveats are listed below.

  • Using tabs (\t) for your indentation will not work.
  • If your Python code is not correctly formatted, you may not get correct indentation.
  • The extension works by registering the Enter key as a keyboard shortcut. The conditions when the shortcut is triggered have been heavily restricted, but there may still be times this extension is unexpectedly overriding Enter behavior. Specifically, vim related plugins seem to require special attention. See the when clause in package.json.

If you experience any problems, please submit an issue, or a pull request.