Regular expressions (python) for string manipulation

re.search(pattner, string[, flags])   #searches *anywhere* in the string.  
re.match(pattern, string[, flags])    #searches at the *beginning* of the string.  
re.findall(pattern, string[, flags])  #returns all matches as a list of strings  
re.split(pattern, string[, maxsplit, flags]) #returns list of strings 

matchobject.group()     #returns is the matching text.
                        #group(0) is the entire match;
                        #.group(1) si the first parenthesized subgroup. 
                        #Multiple arguments such as .group(1, 2) give us a tuple.  

re.sub(pattern, repl, string[, count, flags])     # replace instances by repl.  
re.split()                                        #split string by the occurrences of pattern. If capturing parentheses are used in pattern, then the text of all groups in the pattern are also returned as part of the resulting list.  
re.sub (pattern, repl, string,  count=0, flags=0)  #return the string obtained by replacing the leftmost non-overlapping occurrences of pattern in string. `count` is the maximum number of pattern occurrences to be replaced.  

re.compile(pattern[, flags])  # compiles a RegExp pattern into a RegexObject , which can be used for matching using its **match()** and **search()** methods.    
re.I,  re.IGNORECASE          #  Ignore capital characters.