python re match code example
Example 1: python replace regex
import re
s = "Example String"
replaced = re.sub('[ES]', 'a', s)
print replaced
Example 2: python pattern matching example
import re
pattern = re.compile('[a-zA-Z ]+')
message = "Weather is nice"
if pattern.match(message).group() == message:
print("match")
else:
print("no match")
Example 3: python re compile
import re
prog = re.compile(pattern)
result = prog.match(string)
result = re.match(pattern, string)
Example 4: re.match() python
import re
pattern = '^a...s$'
test_string = 'abyss'
result = re.match(pattern, test_string)
if result:
print("Search successful.")
else:
print("Search unsuccessful.")
Example 5: Python Regex documentation\
>>> import re
>>> m = re.search('(?<=abc)def', 'abcdef')
>>> m.group(0)
'def'
Example 6: regular expression syntax python
1. A fixed string -> abc123
2. Arbitrary repetition -> a*b ( "*" means that you can have an arbitrary
number (possibly 0) of the previous char
3. Repeat character at least once -> a+b
4. Repeat character at most once -> a?b
5. Repeat a character a fixed number of timers -> a{5}
6. Repeat a pattern a fixed number of times -> (a*b){3}
7. Repeat a character or pattern a variable number of times -> a{2,4}
8. Choice of several characters -> [ab]c
9. Arbitrary mixture of several characters -> [ab]*c
10. Ranges of characters -> [A-H][a-z]*
11. Characters OTHER than particular one -> [^AB]
12. Choice of several expressions -> Dr|Mr|Ms|Mrs
13. Nesting expressions -> ([A-Z][a-z][0-9])*
14. Start of a line -> ^ab
15. End of a line -> ab$
1. Special characters -> \[
2. Any charactter 'except' newline -> .
3. Nongreedy evaluation -> <.*>?
4. Whitespace -> \s