Find below are online regex tester
https://regex101.com/
https://pythex.org/
http://www.pyregex.com/
https://www.debuggex.com/
Here you insert your regular expression and get the test result.
Thank you !!!rows = 6 #Pattern(1,121,12321,1234321,123454321)
for i in range(1, rows + 1):
for j in range(1, i - 1):
print(j, end=" ")
for j in range(i - 1, 0, -1):
print(j, end=" ")
print()import re
# Regex Cheat sheet : https://www.dataquest.io/blog/regex-cheatsheet/
# Regex python tester : https://pythex.org/
# re doc : https://docs.python.org/3/library/re.html
text = "i like train"
reg = r"[a-c]" #the group of char a to c
if re.match(reg, text): #Check if regex is correct
print(text)
else:
print("Not any match")import re
# Compile a regular expression pattern into a regular expression object, which can be used for matching using its match(), search() and other methods, described below.
prog = re.compile(pattern)
result = prog.match(string)
# is equivalent to
result = re.match(pattern, string)import re
>>> m = re.search('(?<=abc)def', 'abcdef')
>>> m.group(0)
'def'# Recursive Python3 program to find if a given pattern is
# present in a text
def exactMatch(text, pat, text_index, pat_index):
if text_index == len(text) and pat_index != len(pat):
return 0
# Else If last character of pattern reaches
if pat_index == len(pat):
return 1
if text[text_index] == pat[pat_index]:
return exactMatch(text, pat, text_index+1, pat_index+1)
return 0
# This function returns true if 'text' contain 'pat'
def contains(text, pat, text_index, pat_index):
# If last character of text reaches
if text_index == len(text):
return 0
# If current characters of pat and text match
if text[text_index] == pat[pat_index]:
if exactMatch(text, pat, text_index, pat_index):
return 1
else:
return contains(text, pat, text_index+1, pat_index)
# If current characters of pat and tex don't match
return contains(text , pat, text_index+1, pat_index)
# Driver program to test the above function
print(contains("geeksforgeeks", "geeks", 0, 0))
print(contains("geeksforgeeks", "geeksquiz", 0, 0))
print(contains("geeksquizgeeksquiz", "quiz", 0, 0))
# This code is contributed by ankush_953.