Series.str.
startswith
Test if the start of each string element matches a pattern.
Equivalent to str.startswith().
str.startswith()
pat (str) – Character sequence. Regular expressions are not accepted.
na (object, default NaN) – 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 StringDtype, pandas.NA is used.
numpy.nan
StringDtype
pandas.NA
A Series of booleans indicating whether the given pattern matches the start of each string element.
Series or Index of bool
参见
str.startswith
Python standard library string method.
Series.str.endswith
Same as startswith, but tests the end of string.
Series.str.contains
Tests if string element contains a pattern.
实际案例
>>> import mars.tensor as mt >>> import mars.dataframe as md >>> s = md.Series(['bat', 'Bear', 'cat', mt.nan]) >>> s.execute() 0 bat 1 Bear 2 cat 3 NaN dtype: object
>>> s.str.startswith('b').execute() 0 True 1 False 2 False 3 NaN dtype: object
Specifying na to be False instead of NaN.
>>> s.str.startswith('b', na=False).execute() 0 True 1 False 2 False 3 False dtype: bool