Python字符串处理

导入string模块

# coding=utf-8
import string

每个单词首字母大写

print string.capwords('He is a teacher.')
# >>>He Is A Teacher.

替换字符串中的字符

s1 = string.maketrans('abc', '123')
s2 = 'abcabcabc'
print s2.translate(s1)
# 123123123

字符串模板

values = {'name': 'Tom'}
t = string.Template("""
1.他的名字是:$name
2.输出美元符号:$$
3.${name}是个好同志
""")
print t.safe_substitute(values)
# 1.他的名字是:Tom
# 2.输出美元符号:$
# 3.Tom是个好同志

高级字符串模板

s1 = '''
输出百分号:%%
中间有_的变量会被替换掉:%abc_abc
中间没有_的变量不会被替换:%abcabc
'''
values = {'abc_abc': '被替换',
          'abcabc': '不会被替换'}


class MyTemplate(string.Template):
    # 新建模板类继承自string.Template
    delimiter = '%'
    # %符号为匹配字符
    idpattern = '[a-z]+_[a-z]+'
    # 设置匹配模式,只有中间有_的变量会被匹配


t = MyTemplate(s1)
print t.safe_substitute(values)
# 输出百分号:%
# 中间有_的变量会被替换掉:被替换
# 中间没有_的变量不会被替换:%abcabc

调整字符串的缩进、宽度

import textwrap

s1 = '''
Every parent will worry about their children, 
so they teach the children many things, 
just in case they will meet the bad guy. 
My mother always tells me not to talk 
to the strangers or accept the food from them, 
or I may never see them again. 
I keep her words in mind, so I can avoid the potential dangers. 
'''

s2 = textwrap.dedent(s1.strip())  # 去掉字符串前后空格,并且字符串向左移
print textwrap.fill(s2,
                    70,  # 调整每行宽度
                    initial_indent='',  # 初始缩进
                    subsequent_indent=' ' * 4  # 后面行缩进
                    )
# Every parent will worry about their children,  so they teach the
#     children many things,  just in case they will meet the bad guy.
#     My mother always tells me not to talk to the strangers or accept
#     the food from them,  or I may never see them again. I keep her
#     words in mind, so I can avoid the potential dangers.