split() / join() 拆分和组合
#split() 通过指定分隔符对字符串进行切片（拆分）,默认空格符 lan = "python ruby c c++ swift" lan.split() #['python', 'ruby', 'c', 'c++', 'swift'] #传入符号',' todos = "download python, install, download ide, learn" todos.split(', ') #['download python', 'install', 'download ide', 'learn'] #把它们组合成字符串 ','.join(['download python', 'install', 'download ide', 'learn']) #'download python,install,download ide,learn'
replace() 替换
#replace() 第三个参数为代替几个 s = 'I like C. I like C++. I like Python' s.replace('like', 'hate') #'I hate C. I hate C++. I hate Python' s.replace('like', 'hate', 1) #'I hate C. I like C++. I like Python'
布局center() : 前后留空 ljust()：后面留空 rjust()：前面留空
align = 'Learn how to align' align.center(30) #' Learn how to align ' align.ljust(30) #'Learn how to align ' align.rjust(30) #' Learn how to align' ralign = align.rjust(30) ralign.strip() #'Learn how to align'
eval()： 将字符串处理为可以运算的类型
# eval() str1 = '1+2' print(str1) #输出1+2 print(eval(str1)) #输出3
format() ：格式化字符串 （New style in Python 3.6）
format(输出项，[,格式化字符串])
格式化输出 1）利用字符串格式化运算符%。 格式化字符串%（输出项1，输出项2....）
%% 百分号
%s 字符串
%c 字符
%d 带符号整数 （10进制）
%o 带符号整数 （8进制）
%x或者%X 带符号整数（16进制）
%e或者%E 浮点数字（科学计数法）
%f或者%F 浮点数字（带小数点）
%g或者%G 根据大小来选择
%e %f %*.*f %（项1，项2，输出项） 例如 %*.*f%(6,2,3.145) 等同 %6.2f%3.145
#格式化字符串的函数 str.format()，它增强了字符串格式化的功能。基本语法是通过 {} 和 : 来代替以前的 % print('%s %s' % ('one', 'two')) print('{} {}'.format('one', 'two')) print('%d %d' % (1, 2)) print('{} {}'.format(1, 2)) #one two #one two #1 2 #1 2 print('{1} {0}'.format('one', 'two')) #two one a = 5 b = 10 print(f'Five plus ten is {a + b} and not {2 * (a + b)}.') #Five plus ten is 15 and not 30. ''' 格式字符串还可以指定填充字符、对齐方式（其中<表示左对齐，>表示右对齐、^表示居中、==代表填充字符位于 符号和数字之间）、符号（其中+表示正号，-表示负号） ''' >>>format(65,"c") A >>>print(format(3.145,"6.2f")) 3.15 >>>print(format(3.145,"-6.2f")) 3.15 >>>print(format(3.145,"+6.2f")) +3.15 >>>print(format(3.145,"<6.2f")) 3.15 >>>print(format(3.145,">6.2f")) 3.15 >>>print(format(3.145,"><6.2f")) 3.15>> >>>print(format(3.145,"<=6.2f")) <<3.15 >>>print(format(3.145,"=6.2f")) 3.15 >>>print(format(3.145,"^6.2f")) 3.15 >><print(format(3.145,"0=+10")) +00003.145
其他
#以下函数都是返回新的值，不影响原来的字符串 kk = "Python description: Python is a programming language that lets you work quickly and integrate systems more effectively." kk.startswith('Python') #True kk.endswith('effectively.') #True kk.find('language') #44 #检测字符串是否由字母和数字组成 kk.isalnum() #False kk.count("Python") #2 #移除字符串头尾指定的字符（默认为空格或换行符）或字符序列 kk.strip('.') #'Python description: Python is a programming language that lets you work quickly and integrate systems more effectively' kk.upper() #'PYTHON DESCRIPTION: PYTHON IS A PROGRAMMING LANGUAGE THAT LETS YOU WORK QUICKLY AND INTEGRATE SYSTEMS MORE EFFECTIVELY.' kk.lower() #'python description: python is a programming language that lets you work quickly and integrate systems more effectively.' kk.title() #每个单词开头都大写 #'Python Description: Python Is A Programming Language That Lets You Work Quickly And Integrate Systems More Effectively.' kk.capitalize() #首个单词开头大写，后面不大写 #Python description: python is a programming language that lets you work quickly and integrate systems more effectively. kk.swapcase() #每个字母大小写调换 #pYTHON DESCRIPTION: pYTHON IS A PROGRAMMING LANGUAGE THAT LETS YOU WORK QUICKLY AND INTEGRATE SYSTEMS MORE EFFECTIVELY.