Simple use of python string method, python string method

Simple use of python string method, python string method

Learn how to use the python string method. Make a trial of each method listed in the book and record the results to facilitate future queries.

(1) s. capitalize (); function: returns a copy of the string and upper-case the first letter. Use:

　　

1 >>> s = 'wwwwww'2 >>> scap = s.capitalize()3 >>> scap 4 'Wwwwww'

(2) s. center (width, char); function: returns a string with the length of width in the middle of the s string. By default, other parts are filled with spaces. Otherwise, the char parameter is used. Example:

>>> s 'wwwwww'>>> s = 'wwwwww'>>> scen = s.center(20)>>> scen'       wwwwww       '>>> scen0 = s.center(20,'Y')>>> scen0'YYYYYYYwwwwwwYYYYYYY'>>> 

(3) s. count (t, start, end); function: return the number of t in string s (or in the string's sub-segment ). Example:

>>> scen0'YYYYYYYwwwwwwYYYYYYY'>>> scoun = scen0.count('w',0,19)>>> scoun6

(4) s. endswith (x, start, end); function: If s (or split with start and end) ends with string x, True is returned; otherwise, False is returned.

1 >>> scen0 2 'YYYYYYYwwwwwwYYYYYYY'3 >>> sends0 = scen0.endswith('Y',1,19)4 >>> sends05 True6 >>> sends1 = scen0.endswith('w',1,10)7 >>> sends18 True

(5) s. find (t, start, end); function: returns the leftmost position of string t in s (or start: end slice). If t is not found,-1 is returned ,. Use s. rfind (t, start, end) to find the rightmost position of t. Example:

1 >>> s2 'YYYYYYYwwwwwwYYYYYYY'3 >>> t = 'w'4 >>> sfind = s.find(t,0,19)5 >>> sfind6 77 >>> srfind = s.rfind(t,1,19)8 >>> srfind9 12

(6) s. isalnum (); function: If s is not empty, and each character isLetter/DigitReturns True.

1 >>> s2 'YYYYYYYwwwwwwYYYYYYY'3 >>> sisa = s.isalnum()4 >>> sisa5 True

(7) s. isalpha (); function: If s is not empty, and each character isLetterReturns True.

>>> s'YYYYYYYwwwwwwYYYYYYY'>>> sisal = s.isalpha()>>> sisalTrue>>> s1'ssss0000'>>> sisal0 = s1.isalpha()>>> sisal0False

(8) s. isdigit (); function: If s is not empty and each character is an ASCII number, True is returned.

1 >>> sdigit = 'www000'2 >>> sd = sdigit.isdigit()3 >>> sd4 False5 >>> sdigit0 = '1234567890'6 >>> sd0 = sdigit0.isdigit()7 >>> sd08 True

(9) s. islower (); function: If s has at least one lowercase character and all lowercase characters are lowercase, True is returned.

>>> s0 = '1234567890'>>> s0lower = s0.islower()>>> s0lowerFalse>>> s1 = '1234WWW'>>> s1lower = s1.islower()>>> s1lowerFalse>>> s2 = '123456789w'>>> s2lower = s2.islower()>>> s2lowerTrue

(10) s. isspace (); function: If s is not empty and every character in s is a blank character, True is returned.

>>> s = ''>>> s0 = s.isspace()>>> s0False>>> s = '    '>>> s0 = s.isspace()>>> s0True

(11) s. istitle (); function: returns True if s is a non-empty string with uppercase letters.

>>> s = 'wy'>>> s0 = s.istitle()>>> s0False>>> s = 'Wy'>>> s0 = s.istitle()>>> s0True

(12) s. isupper (); function: returns True if s has at least one character that can be written in uppercase and all characters that can be written in uppercase.

>>> s = 'wy'>>> s0 = s.isupper()>>> s0False>>> s = 'Wy'>>> s0 = s.isupper()>>> s0False>>> s = 'WY'>>> s0 = s.isupper()>>> s0True

(13) s. join (seq); function: return the result of sequence seq after joining, and s is between every two items.

1 >>> seq = 'WWWWWWW'2 >>> s = 'y'3 >>> snew = s.join(seq)4 >>> snew5 'WyWyWyWyWyWyW'

(14) s. lower (); function: converts characters in s to lowercase letters.

1 >>> snew2 'WyWyWyWyWyWyW'3 >>> s =snew.lower()4 >>> s5 'wywywywywywyw'

(15) s. replace (t, u, n); function: returns a copy of s, where each t (or up to n) is replaced by u.

>>> s'wywywywywywyw'>>> sre = s.replace('w','W')>>> sre'WyWyWyWyWyWyW'>>> s'wywywywywywyw'>>> sre = s.replace('w','W',4)>>> sre'WyWyWyWywywyw'

(16) s. swapcase (); function: return a copy of s, and uppercase and lowercase.

1 >>> s = 'WyWyWyWy'2 >>> ssw = s.swapcase()3 >>> ssw4 'wYwYwYwY'

(17) s. zfill (w); function: returns a copy of s. If it is shorter than w, add 0 at the beginning to set its length to w.

1 >>> s = 'www'2 >>> sz = s.zfill(10)3 >>> sz4 '0000000www'