import re

@xl_func()
@xl_arg('regexp', 'str')
@xl_arg('txt', 'str')
def RESearch(regexp, txt, rtn = 3):
    """
Returns a Match object if there is a match for regexp anywhere in txt

:param regexp: Regular expression
:param txt: Text to be searched
:param rtn: Value to be returned; 1 = span array for match location, 2 = input txt, 3 = list of matches (default)
    """
    x = re.search(regexp, txt)
    try:
        # span() string group()
        if rtn == 1:
            return x.span()
        elif rtn == 2:
            return x.string
        else:
            return x.group()
    except:
        return "No match"

@xl_func()
@xl_arg('regexp', 'str')
@xl_arg('txt', 'str')
def REFindall(regexp, txt):
    """
Returns a list containing all matches 

:param regexp: Regular expression
:param txt: Text to be searched
    """
    x = re.findall(regexp, txt)
    try:
        return x
    except:
        return "No match"

@xl_func()
@xl_arg('regexp', 'str')
@xl_arg('txt', 'str')
def RESplit(regexp, txt):
    """
Returns a list where the string has been split at all matches 

:param regexp: Regular expression
:param txt: Text to be searched
    """
    x = re.split(regexp, txt)
    try:
        return x
    except:
        return "No match"

@xl_func()
@xl_arg('regexp', 'str')
@xl_arg('replace', 'str')
@xl_arg('txt', 'str')
def RESub(regexp, replace, txt):
    """
Replaces one or many matches with a string 

:param regexp: Regular expression
:param txt: Text to be searched
    """
    x = re.sub(regexp, replace, txt)
    try:
        return x
    except:
        return "No match"