@register_function(scope='<STR_LIT:str>')<EOL>def str_contains(x, pattern, regex=True):
return _to_string_sequence(x).search(pattern, regex)<EOL>
Check if a string pattern or regex is contained within a sample of a string column.

    :param str pattern: A string or regex pattern
    :param bool regex: If True,
    :returns: an expression which is evaluated to True if the pattern is found in a given sample, and it is False otherwise.

    Example:

    >>> import vaex
    >>> text = ['Something', 'very pretty', 'is coming', 'our', 'way.']
    >>> df = vaex.from_arrays(text=text)
    >>> df
      #  text
      0  Something
      1  very pretty
      2  is coming
      3  our
      4  way.

    >>> df.text.str.contains('very')
    Expression = str_contains(text, 'very')
    Length: 5 dtype: bool (expression)
    ----------------------------------
    0  False
    1   True
    2  False
    3  False
    4  False