Python中字符串常用的方法
str = "this is string example....wow!!!";print "str.capitalize() : ", str.capitalize()#output resultstr.capitalize() : This is string example....wow!!!
str = "this is string example....wow!!!";sub = "i";print "str.count(sub, 4, 40) : ", str.count(sub, 4, 40)sub = "wow";print "str.count(sub) : ", str.count(sub)
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#output resultstr.count(sub, 4, 40) : 2str.count(sub, 4, 40) : 1
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?str = "this is string example....wow!!!";suffix = "wow!!!";print str.endswith(suffix);print str.endswith(suffix,20);suffix = "is";print str.endswith(suffix, 2, 4);print str.endswith(suffix, 2, 6);#output resultTrueTrueTrueFalse
str1 = "this is string example....wow!!!";str2 = "exam";print str1.find(str2);print str1.find(str2, 10);print str1.find(str2, 40);#result1515-1
str = "this is string example....wow!!!";str = "exam";print str.index(str);print str.index(str, 10);print str.index(str, 40);#result1515Traceback (most recent call last): File "test.py", line 8, in print str.index(str, 40);ValueError: substring not found?isalnum()判断字符串是否全是字母和数字（要么全是字母，要么全是数字，要么全是数字和字母）例如：
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str = "this2009"; # No space in this stringprint str.isalnum();str = "this is string example....wow!!!";print str.isalnum();#resultTrueFalse?isalpha()方法判断字符串内容全是字母。例如：
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str = "this"; # No space & digit in this stringprint str.isalpha();str = "this is string example....wow!!!";print str.isalpha();#resultTrueFalse?isdecimal()和isnumeric()判断字符串是否全是数字，该字符串必须是unicode object。例如：
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str = u"this2009"; print str.isdecimal();str = u"23443434";print str.isdecimal();#resultFalseTrue?str = "123456"; # Only digit in this stringprint str.isdigit();str = "this is string example....wow!!!";print str.isdigit();#resultTrueFalse?islower()判断字符串中所有的字母是否都是小写。str = "THIS is string example....wow!!!"; print str.islower();str = "this is string example....wow!!!";print str.islower();#resultFalseTrue?
str = " \t\n"; #include tab,spaceprint str.isspace();str = "This is string example....wow!!!";print str.isspace();#resultTrueFalse
?istitle()判断字符串中，每个单词的首字母是否都是大写。例如:
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str = "This Is String Example...Wow!!!";print str.istitle();str = "This is string example....wow!!!";print str.istitle();#resultTrueFalse
?str = "-";seq = ("a", "b", "c"); # This is sequence of strings.print str.join( seq );#resulta-b-c len(str)str = "this is string example....wow!!!";print str.swapcase();str = "THIS IS STRING EXAMPLE....WOW!!!";print str.swapcase();#resultTHIS IS STRING EXAMPLE....WOW!!!this is string example....wow!!! str = " this is string example....wow!!! ";print str.lstrip();str = "88888888this is string example....wow!!!8888888";print str.lstrip('8');#resultthis is string example....wow!!!this is string example....wow!!!8888888 ? ? ? ?maketrans()看例子吧：例子中实际上是把对应的字母替换成数字。 ? ? str = "this is really a string example....wow!!!";print "Max character: " + max(str);str = "this is a string example....wow!!!";print "Max character: " + max(str);#resultMax character: yMax character: x ?replace()用新字符替换旧字符 ?rfind()返回指定指定范围内，子串最后出现的索引，找不到返回-1。例如： ?str = "this is string example....wow!!!";print str.rjust(50, '0');#result000000000000000000this is string example....wow!!! ?zfill()用“0”进行填充。看例子吧： ? ? ? str = "Line1-abcdef \nLine2-abc \nLine4-abcd";print str.split( );print str.split(' ', 1 );#result['Line1-abcdef', 'Line2-abc', 'Line4-abcd']['Line1-abcdef', '\nLine2-abc \nLine4-abcd'] ?str = "this is string example....wow!!!";print str.title();#resultThis Is String Example....Wow! from string import maketrans # Required to call maketrans function.intab = "aeiou"outtab = "12345"trantab = maketrans(intab, outtab)str = "this is string example....wow!!!";print str.translate(trantab, 'xm');#resultth3s 3s str3ng 21pl2....w4w!!! ?str = " this is string example....wow!!! ";print str.rstrip();str = "88888888this is string example....wow!!!8888888";print str.rstrip('8');#result this is string example....wow!!!88888888this is string example....wow!!!from string import maketrans # Required to call maketrans function.intab = "aeiou"outtab = "12345"trantab = maketrans(intab, outtab)str = "this is string example....wow!!!";print str.translate(trantab);#resultth3s 3s str3ng 2x1mpl2....w4w!!!
str = "this is string example....wow!!! this is really string";print str.replace("is", "was"); print str.replace("is", "was", 3);#resultthwas was string example....wow!!! thwas was really stringthwas was string example....wow!!! thwas is really stringstr = "this is really a string example....wow!!!";str1 = "is";print str.rfind(str1);print str.rfind(str1, 0, 10);print str.rfind(str1, 10, 0);print str.find(str1);print str.find(str1, 0, 10);print str.find(str1, 10, 0);#result55-122-1
str = "this is string example....wow!!!";print str.zfill(40);print str.zfill(50);#result00000000this is string example....wow!!!000000000000000000this is string example....wow!!!
