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module  pixeltable.functions.string

Pixeltable UDFs for StringType. It closely follows the Pandas pandas.Series.str API. Example:

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iterator  string_splitter()

Signature
Iterator over chunks of a string. The string is chunked according to the specified separators. The iterator yields a text field containing the text of the chunk. Chunked text will be cleaned with ftfy.fix_text to fix up common problems with unicode sequences. Parameters:
  • separators (str): separators to use to chunk the document. Currently the only supported option is 'sentence'.
Examples: This example assumes an existing table tbl with a column text of type pxt.String. Create a view that splits all strings on sentence boundaries:

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udf  capitalize()

Signature
Return string with its first character capitalized and the rest lowercased. Equivalent to str.capitalize().

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udf  casefold()

Signature
Return a casefolded copy of string. Equivalent to str.casefold().

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udf  center()

Signature
Return a centered string of length width. Equivalent to str.center(). Parameters:
  • width (pxt.Int): Total width of the resulting string.
  • fillchar (pxt.String): Character used for padding.

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udf  contains()

Signature
Test if string contains a substring. Parameters:
  • substr (pxt.String): string literal or regular expression
  • case (pxt.Bool): if False, ignore case

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udf  contains_re()

Signature
Test if string contains a regular expression pattern. Parameters:
  • pattern (pxt.String): regular expression pattern
  • flags (pxt.Int): flags for the re module

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udf  count()

Signature
Count occurrences of pattern or regex. Parameters:
  • pattern (pxt.String): string literal or regular expression
  • flags (pxt.Int): flags for the re module

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udf  endswith()

Signature
Return True if the string ends with the specified suffix, otherwise return False. Equivalent to str.endswith(). Parameters:
  • substr (pxt.String): string literal

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udf  fill()

Signature
Wraps the single paragraph in string, and returns a single string containing the wrapped paragraph. Equivalent to textwrap.fill(). Parameters:
  • width (pxt.Int): Maximum line width.
  • kwargs (Any): Additional keyword arguments to pass to textwrap.fill().

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udf  find()

Signature
Return the lowest index in string where substr is found within the slice s[start:end]. Equivalent to str.find(). Parameters:
  • substr (pxt.String): substring to search for
  • start (pxt.Int): slice start
  • end (pxt.Int | None): slice end

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udf  findall()

Signature
Find all occurrences of a regular expression pattern in string. Equivalent to re.findall(). Parameters:
  • pattern (pxt.String): regular expression pattern
  • flags (pxt.Int): flags for the re module

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udf  format()

Signature
Perform string formatting. Equivalent to str.format().

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udf  fullmatch()

Signature
Determine if string fully matches a regular expression. Equivalent to re.fullmatch(). Parameters:
  • pattern (pxt.String): regular expression pattern
  • case (pxt.Bool): if False, ignore case
  • flags (pxt.Int): flags for the re module

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udf  index()

Signature
Return the lowest index in string where substr is found within the slice [start:end]. Raises ValueError if substr is not found. Equivalent to str.index(). Parameters:
  • substr (pxt.String): substring to search for
  • start (pxt.Int): slice start
  • end (pxt.Int | None): slice end

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udf  isalnum()

Signature
Return True if all characters in the string are alphanumeric and there is at least one character, False otherwise. Equivalent to [str.isalnum()](https://docs.python.org/3/library/stdtypes.html#str.isalnum

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udf  isalpha()

Signature
Return True if all characters in the string are alphabetic and there is at least one character, False otherwise. Equivalent to str.isalpha().

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udf  isascii()

Signature
Return True if the string is empty or all characters in the string are ASCII, False otherwise. Equivalent to str.isascii().

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udf  isdecimal()

Signature
Return True if all characters in the string are decimal characters and there is at least one character, False otherwise. Equivalent to str.isdecimal().

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udf  isdigit()

Signature
Return True if all characters in the string are digits and there is at least one character, False otherwise. Equivalent to str.isdigit().

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udf  isidentifier()

Signature
Return True if the string is a valid identifier according to the language definition, False otherwise. Equivalent to str.isidentifier()

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udf  islower()

Signature
Return True if all cased characters in the string are lowercase and there is at least one cased character, False otherwise. Equivalent to str.islower()

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udf  isnumeric()

Signature
Return True if all characters in the string are numeric characters, False otherwise. Equivalent to str.isnumeric()

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udf  isspace()

Signature
Return True if there are only whitespace characters in the string and there is at least one character, False otherwise. Equivalent to str.isspace()

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udf  istitle()

Signature
Return True if the string is a titlecased string and there is at least one character, False otherwise. Equivalent to str.istitle()

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udf  isupper()

Signature
Return True if all cased characters in the string are uppercase and there is at least one cased character, False otherwise. Equivalent to str.isupper()

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udf  join()

Signature
Return a string which is the concatenation of the strings in elements. Equivalent to str.join()

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udf  len()

Signature
Return the number of characters in the string. Equivalent to len(str)

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udf  ljust()

Signature
Return the string left-justified in a string of length width. Equivalent to str.ljust() Parameters:
  • width (pxt.Int): Minimum width of resulting string; additional characters will be filled with character defined in fillchar.
  • fillchar (pxt.String): Additional character for filling.

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udf  lower()

Signature
Return a copy of the string with all the cased characters converted to lowercase. Equivalent to str.lower()

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udf  lstrip()

Signature
Return a copy of the string with leading characters removed. The chars argument is a string specifying the set of characters to be removed. If omitted or None, whitespace characters are removed. Equivalent to str.lstrip() Parameters:
  • chars (pxt.String | None): The set of characters to be removed.

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udf  match()

Signature
Determine if string starts with a match of a regular expression Parameters:
  • pattern (pxt.String): regular expression pattern
  • case (pxt.Bool): if False, ignore case
  • flags (pxt.Int): flags for the re module

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udf  normalize()

Signature
Return the Unicode normal form. Equivalent to unicodedata.normalize() Parameters:
  • form (pxt.String): Unicode normal form ('NFC', 'NFKC', 'NFD', 'NFKD')

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udf  pad()

Signature
Pad string up to width Parameters:
  • width (pxt.Int): Minimum width of resulting string; additional characters will be filled with character defined in fillchar.
  • side (pxt.String): Side from which to fill resulting string ('left', 'right', 'both')
  • fillchar (pxt.String): Additional character for filling

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udf  partition()

Signature
Splits string at the first occurrence of sep, and returns 3 elements containing the part before the separator, the separator itself, and the part after the separator. If the separator is not found, return 3 elements containing string itself, followed by two empty strings.

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udf  removeprefix()

Signature
Remove prefix. If the prefix is not present, returns string.

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udf  removesuffix()

Signature
Remove suffix. If the suffix is not present, returns string.

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udf  repeat()

Signature
Repeat string n times.

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udf  replace()

Signature
Replace occurrences of substr with repl. Equivalent to str.replace(). Parameters:
  • substr (pxt.String): string literal
  • repl (pxt.String): replacement string
  • n (pxt.Int | None): number of replacements to make (if None, replace all occurrences)

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udf  replace_re()

Signature
Replace occurrences of a regular expression pattern with repl. Equivalent to re.sub(). Parameters:
  • pattern (pxt.String): regular expression pattern
  • repl (pxt.String): replacement string
  • n (pxt.Int | None): number of replacements to make (if None, replace all occurrences)
  • flags (pxt.Int): flags for the re module

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udf  reverse()

Signature
Return a reversed copy of the string. Equivalent to str[::-1].

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udf  rfind()

Signature
Return the highest index where substr is found, such that substr is contained within [start:end]. Equivalent to str.rfind(). Parameters:
  • substr (pxt.String): substring to search for
  • start (pxt.Int | None): slice start
  • end (pxt.Int | None): slice end

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udf  rindex()

Signature
Return the highest index where substr is found, such that substr is contained within [start:end]. Raises ValueError if substr is not found. Equivalent to str.rindex().

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udf  rjust()

Signature
Return the string right-justified in a string of length width. Equivalent to str.rjust(). Parameters:
  • width (pxt.Int): Minimum width of resulting string.
  • fillchar (pxt.String): Additional character for filling.

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udf  rpartition()

Signature
This method splits string at the last occurrence of sep, and returns a list containing the part before the separator, the separator itself, and the part after the separator.

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udf  rstrip()

Signature
Return a copy of string with trailing characters removed. Equivalent to str.rstrip(). Parameters:
  • chars (pxt.String | None): The set of characters to be removed. If omitted or None, whitespace characters are removed.

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udf  slice()

Signature
Return a slice. Parameters:
  • start (pxt.Int | None): slice start
  • stop (pxt.Int | None): slice end
  • step (pxt.Int | None): slice step

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udf  slice_replace()

Signature
Replace a positional slice with another value. Parameters:
  • start (pxt.Int | None): slice start
  • stop (pxt.Int | None): slice end
  • repl (pxt.String | None): replacement value

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udf  startswith()

Signature
Return True if string starts with substr, otherwise return False. Equivalent to str.startswith(). Parameters:
  • substr (pxt.String): string literal

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udf  strip()

Signature
Return a copy of string with leading and trailing characters removed. Equivalent to str.strip(). Parameters:
  • chars (pxt.String | None): The set of characters to be removed. If omitted or None, whitespace characters are removed.

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udf  swapcase()

Signature
Return a copy of string with uppercase characters converted to lowercase and vice versa. Equivalent to str.swapcase().

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udf  title()

Signature
Return a titlecased version of string, i.e. words start with uppercase characters, all remaining cased characters are lowercase. Equivalent to str.title().

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udf  upper()

Signature
Return a copy of string converted to uppercase. Equivalent to str.upper().

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udf  wrap()

Signature
Wraps the single paragraph in string so every line is at most width characters long. Returns a list of output lines, without final newlines. Equivalent to textwrap.fill(). Parameters:
  • width (pxt.Int): Maximum line width.
  • kwargs (Any): Additional keyword arguments to pass to textwrap.fill().

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udf  zfill()

Signature
Pad a numeric string with ASCII 0 on the left to a total length of width. Equivalent to str.zfill(). Parameters:
  • width (pxt.Int): Minimum width of resulting string.
Last modified on June 12, 2026