import re

x = re.match("a", "cat") 	# None, 'cat' doesn't start with 'a'
print(x)

x = re.search("a", "cat")	# Returns a match object, 'cat' has an 'a' in it
print(x)

x = re.search("c", "dog")	# None, 'dog' doesn't have a 'c' in it
print(x)

s = re.split("[ab]", "carbs")	# Split "carbs" on a or b
print(s)

s = re.sub("[0-9]", "-", "R2D2") # replace digits with dashes
print(s)