Test if the start of each string element matches a pattern.
Equivalent to str.startswith().
Character sequence or tuple of strings. Regular expressions are not accepted.
Object shown if element tested is not a string. The default depends on dtype of the array. For object-dtype, numpy.nan is used. For the nullable StringDtype, pandas.NA is used. For the "str" dtype, False is used.
A Series of booleans indicating whether the given pattern matches the start of each string element.
See also
str.startswithPython standard library string method.
Series.str.endswithSame as startswith, but tests the end of string.
Series.str.containsTests if string element contains a pattern.
Examples
>>> s = pd.Series(['bat', 'Bear', 'cat', np.nan])
>>> s
0 bat
1 Bear
2 cat
3 NaN
dtype: object
>>> s.str.startswith('b')
0 True
1 False
2 False
3 NaN
dtype: object
>>> s.str.startswith(('b', 'B'))
0 True
1 True
2 False
3 NaN
dtype: object
Specifying na to be False instead of NaN.
>>> s.str.startswith('b', na=False)
0 True
1 False
2 False
3 False
dtype: bool
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https://pandas.pydata.org/pandas-docs/version/2.3.0/reference/api/pandas.Series.str.startswith.html