otp.Operation.str.substr#

_StrAccessor.substr(start, n_bytes=None, rtrim=False, *, utf8=False)#

Return n_bytes characters starting from start.

For a positive start return num_bytes of the string, starting from the position specified by start (0-based). For a negative start, the position is counted from the end of the string. If the n_bytes parameter is omitted, returns the part of the input string starting at start till the end of the string.

Parameters:

start (int or Column or Operation) – Index of first symbol in substring
n_bytes (int or Column or Operation) – Number of bytes in substring
rtrim (bool) – If set to True, original string will be trimmed from the right side before getting the substring, this can be useful with negative start index.
utf8 (bool) – If set, then UTF-8 format is supported.

Returns:

Substring of string (n_bytes length starting with start).

Return type:

Operation

Examples

>>> data = otp.Ticks(X=['abcdef', '12345     '], START_INDEX=[2, 1], N=[2, 3])
>>> data['FIRST_3'] = data['X'].str.substr(0, 3)
>>> data['LAST_3'] = data['X'].str.substr(-3, rtrim=True)
>>> data['CENTER'] = data['X'].str.substr(data['START_INDEX'], data['N'])
>>> otp.run(data)
                     Time       X  START_INDEX  N FIRST_3 LAST_3 CENTER
0 2003-12-01 00:00:00.000  abcdef            2  2     abc    def     cd
1 2003-12-01 00:00:00.001   12345            1  3     123    345    234