1.python string related operations
= S1 " Hello " S2 = " World! " # removed string left and right spaces S1 = s1.strip () S2 = s2.strip () # string concatenation S = S1 + S2 # Find character or substring s_index = s .index ( ' Hello ' ) # string case conversion S3 = "the ABC" S4 = " ABC " s3_lower = s3.lower () s4_upper = s4.upper () # flip string s_reverse = S [:: -. 1 ] #Search string s_find s.find = ( " Hello " ) # split string S5 = " A, B, C, D, E " s5_split = s5.split ( " ,")
Import Re from the Collections Import Counter # to obtain the maximum number of characters appears in the string DEF count_char (str): str = str.lower () RES = re.findall ( " [az] " , str) COUNT = Counter (RES) return [K for K, V in count.items () IF V == max (List (count.values ()))]
2. Regular expressions (many tutorials online, the key is to understand what it means each of which represents, but also to write, in fact, no big deal, do not write here) to only write about is how to use python