PyCharm 2024.2 Help

Live template variables

When you expand a live template abbreviation, its variables either appear as input fields where you can type values or are replaced with values. These may be default values that you can modify or values calculated using functions.

To declare variables within templates, use the following format: $VAR$.

In expressions, use variable names without opening and closing dollar characters $, for example, lowercaseAndDash(ComponentName).

Define each variable using an expression and provide a default value for cases when the expression fails to evaluate.

This expression may contain the following constructs:

  • String constants in double quotes

  • Names of other variables defined in a live template

  • with possible arguments

Configure template variables

  1. In the Settings dialog (Ctrl+Alt+S) , go to Editor | Live Templates.

  2. Select a template where you want to configure variables.

  3. Specify variables in the template text and click Edit Variables.

  4. In the Edit Template Variables dialog, you can do the following for each variable:

    • Change the variable name.

    • Define an expression using predefined functions.

    • Specify the default value for cases when the expression fails to evaluate. The default value should be enclosed in double quotation marks.

    • Specify whether you want to skip the variable when prompting the user for input if the expression evaluated successfully.

    Live template variables

Predefined template variables

PyCharm supports the following predefined live template variables that cannot be modified:

  • $END$ indicates the position of the caret when the code snippet is complete, and you can no longer press Tab to jump to the next variable.

  • $SELECTION$ is used in surround templates and denotes the code fragment to be wrapped. After the template expands, it wraps the selected text as specified in the template. For example, if you select EXAMPLE in your code and invoke the "$SELECTION$" template via the assigned abbreviation or by pressing Ctrl+Alt+T and selecting the desired template from the list, PyCharm will wrap the selection in double quotes as follows: "EXAMPLE".

Functions used in live template variables

The following functions can be used to define live template variables:

Function

Description

blockCommentEnd()

Returns the characters that indicate the end of a block comment in the current language context.

blockCommentStart()

Returns the characters that indicate the start of a block comment in the current language context.

camelCase(<String>)

Converts a string into camelCase.

For example, camelCase("my-text-file"), camelCase("my text file"), and camelCase("my_text_file") all return myTextFile.

capitalize(<String>)

Capitalizes the first letter of a string.

For example, capitalize("name") returns Name. Or you can combine it into capitalize(camelCase("my awesome class")) to get MyAwesomeClass.

capitalizeAndUnderscore(<String>)

Capitalizes all the letters of a string, and inserts an underscore between the parts.

For example, capitalizeAndUnderscore("FooBar"), capitalizeAndUnderscore("foo bar"), and capitalizeAndUnderscore("foo-bar") all return FOO_BAR.

clipboard()

Returns the contents of the system clipboard.

collectionElementName()

Removes _list and plural ending (s).

commentEnd()

Returns the characters that indicate the end of a comment in the current language context. For languages with line comments, the return value is empty.

commentStart()

Returns the characters that indicate the start of a comment in the current language context. For languages with line comments, the return value is the start of a line comment, same as lineCommentStart().

complete()

Invokes code completion at the position of the variable.

completeSmart()

Invokes smart type completion at the position of the variable.

concat(<String>, ...)

Returns a concatenation of all the strings passed to the function as parameters.

For example, concat(date()," ",user()) returns the current system date and username separated with a space.

date([format])

Returns the current system date.

By default, without a parameter, it returns the date in the current system format. To use a different format, provide a parameter according to the SimpleDateFormat specification. For example, the date("Y-MM-d, E, H:m") returns the date formatted as 2020-02-27, Thu, 16:11.

dbColumns()

Returns a list of columns for a table or a view. The dbColumns() is used in context live templates (for example, ins). You can access context live templates by right-clicking an object and selecting SQL Scripts.

dbObjectName()

Returns a name of a table or a view. The dbObjectName() is used in context live templates (for example, top). You can access context live templates by right-clicking an object and selecting SQL Scripts.

decapitalize(<String>)

Replaces the first letter of a string with the corresponding lowercase letter.

For example, decapitalize("Name") returns name.

defaultReturnValues

Returns the default value if the expression is used in the return statement. Uses the errorVariableName parameter if the expression is of the error type.

djangoBlock

Shows completion popup for the available Django blocks.

djangoFilter

Shows completion popup for the available Django filters.

djangoTemplateTags

Shows comFpletion popup for the available Django template tags

djangoVariable

Shows completion popup for the available Django variable.

enum(<String>, ...)

Returns a list of strings suggested for completion when the template expands.

For example, enum("Foo","Bar","Baz") shows a list from which you can choose one of the specified strings.

escapeString(<String>)

Escapes special characters so that the result can be used in a Java string.

For example, it replaces the tab character with \t, the newline character with \n, escapes the backslash as \\, quotes as \", and so on.

expectedType()

Returns the expected type of the expression where the template expands (in the right part of an assignment, after return, as a method parameter, and so on).

Available in the Java context only.

fileName()

Returns the name of the current file with its extension.

fileNameWithoutExtension()

Returns the name of the current file without its extension.

filePath()

Returns the absolute path to the current file.

fileRelativePath()

Returns the current file path relative to the current project. To check what the relative path is for a given file, right-click it and select Copy Reference, or press Ctrl+Alt+Shift+C.

firstWord(<String>)

Returns the first word of the string passed as the parameter.

For example, firstWord("one two three") returns one.

groovyScript(<String>, [arg, ...])

Executes the Groovy script passed as a string.

The first argument is a string with either the text of the script or the path to the file that contains the script. The function passes other optional arguments to the script as values for _1, _2, _3, ..., _n variables. Also, you can access the current editor from inside the script using the _editor variable.

The following example shows a groovyScript() function that converts a given string (the value of another variable, $MyVar$) to upper case letters:

groovyScript("_1.toUpperCase()", MyVar)

The following example shows a groovyScript() function that splits the selected text into words and displays them as a numbered list:

groovyScript("def result = ''; _1.split().eachWithIndex { item, index -> result = result + index.next() + '. ' + item + System.lineSeparator() }; return result;", SELECTION)

The last example uses the SELECTION predefined variable meaning you have to select text and press Ctrl+Alt+T (Surround with) to apply it.

JsArrayVariable()

Returns the name of the current JavaScript array.

jsClassName()

Returns the name of the current JavaScript class.

jsComponentTypeOf()

Returns the type of the current JavaScript component.

jsDefineParameter

Based on the name of the module, returns the parameter from define(["module"], function (<parameter_in_question>>) {}).

jsMethodName()

Returns the name of the current JavaScript method.

jsQualifiedClassName()

Returns the complete name of the current JavaScript class.

jsSuggestDefaultVariableKind(Boolean)

The Boolean parameter determines whether constants are allowed or not in the current context. If no parameter is specified, constants are allowed. When the templates expands, a list is shown with var, let, const options for TypeScript and ES6 and with only one var option for earlier JavaScript versions.

jsSuggestImportedEntityName()

Suggests the name for import statements of the type `import * as $ITEM$ from "$MODULE$"` or `import $ITEM$ from "$MODULE$"` based on the filename.

jsSuggestIndexName()

Returns a suggested name for an index variable from most commonly used ones: i, j, k, and so on. The names that are not used in the current scope yet are shown first.

jsSuggestVariableName()

Returns the suggested name for a variable based on its variable type and initializer expression, according to your code style settings that refer to the variable naming rules. For example, if it is a variable that holds an element within an iteration, PyCharm makes a guess on the most reasonable name, taking into account the name of the container that is iterated.

lineCommentStart()

Returns the characters that indicate the start of a line comment in the current language context.

lineNumber()

Returns the current line number.

lowercaseAndDash(<String>)

Converts a string into lower case and inserts n-dashes as separators. For example, lowercaseAndDash("MyExampleName") and lowercaseAndDash("my example name") both return my-example-name.

pyClassName()

Returns the name of the current Python class (the class where the template is expanded).

pyFunctionName()

Returns the name of the current Python function.

pyIterableVariable()

Enables scope specific completion for the iterable variables.

Using pyIterableVariable() in live templates

regularExpression(<String>, <Pattern>, <Replacement>)

Finds all occurrences of Pattern in a String and replaces them with Replacement. You can specify the pattern as a regular expression to find everything that matches it in the string.

For example, the regularExpression(NAME, "a", "b") expression will replace any letter "a" in the $NAME$ template variable with the letter "b". You can use regexp character classes in the pattern part; for example, regularExpression(NAME, "[a-z]", "b") will replace any letter in the variable. If you want patterns, such as \d or \w, to be considered as regexp character classes, you have to escape the slash so that your pattern looks like "\\d".

showParameterInfo()

Returns the parameter details when adding a parameter to a function or method.

Example of usage:

Show parameter info

snakeCase(<String>)

Converts a string into snake_case. For example, snakeCase("fooBar") and snakeCase("foo bar") both return foo_bar.

spaceSeparated(<String>)

Returns the specified string with spaces as separators. For example, spaceSeparated("fooBar") returns foo Bar and spaceSeparated("Foo_BAR") returns Foo BAR.

spacesToUnderscores(<String>)

Replaces spaces with underscores in the string passed as the parameter. For example, spacesToUnderscores("foo bar BAZ") returns foo_bar_BAZ.

substringBefore(<String>, <Delimeter>)

Returns the substring up to the specified delimiter. This is helpful for removing the extensions in test file names. For example, substringBefore(fileName(),".") returns component-test if used in a file named component-test.js.

time([format])

Returns the current system time.

By default, without a parameter, it returns the time in the current system format. To use a different format, provide a parameter according to the SimpleDateFormat specification. For example, the time("H:m z") returns the time formatted as 13:10 UTC.

typeOfVariable(<String>)

Returns the type of the variable passed as the parameter.

Available in the Java context only.

underscoresToCamelCase(<String>)

Transforms a string with underscores (like snake_case) into camelCase. For example, underscoresToCamelCase(foo_bar_baz) and underscoresToCamelCase(FOO_BaR_baZ) both return fooBarBaz.

underscoresToSpaces(<String>)

Transforms underscores in a string to spaces. For example, underscoresToSpaces(foo_bar_baz) returns foo bar baz and underscoresToSpaces(FOO_BaR_baZ) returns FOO BaR baZ.

user()

Returns the name of the current user.

Example

Let's make a simple live template using variables and functions. It will create a Python class with a predefined class variable and a method. The template will contain three variables:

  • $ClassName$: a name for a new class

  • $Food$: a list of three possible values: "meat", "grass", and "honey"

  • $AnimalName$: the class name starting with a lowercase letter so that it can be used in a sentence

Create a template with variables

  1. Press Ctrl+Alt+S to open settings and then select Editor | Live Templates.

  2. Select the Python group, click the Add button, and select Live Template.

  3. In the Abbreviation field, specify the characters that will be used to expand the template. For example, animal.

  4. In the Template text field, paste the following template:

    class $ClassName$(Animal): food = "$Food$" def animal_food(self): print(f"The $AnimalName$ eats {self.food}.")
    Create a live template
  5. If there is a No applicable contexts warning, click Define and select the context where you want this live template to be available. For example, Python:

    Select the context for the live template
  6. Click Edit Variables and, in the Edit Template Variables dialog, configure the variables:

    • $ClassName$ remains untouched meaning we expect users to type a value when they apply this template.

    • $Food$: in the Expression field, enter enum("meat","grass","honey"). This function allows selecting one of the predefined values when users apply this template.

    • $AnimalName$: in the Expression field, enter decapitalize(ClassName). This function takes the value of the ClassName variable and converts its first letter to the lower case. Select Skip if defined because we don't need to prompt a user for input.

    Live template context

Use live template

  1. Start typing the name of a live template (animal in our example).

  2. Type a value of the variable (a class name in our example) and press Tab to jump to the next variable.

  3. Using the keyboard arrows, select one of the values for the food string.

Last modified: 25 October 2024