python文字列操作

1.文字列接続

# join
a = ['a','b','c','d']
content = ''.join(a)  # 'abcd'

#      
test_str = 'Hello %s! Welcome to %s'%('Tom', 'our home')

# tuple 
content = '%s%s%s%s'%tuple(a) # abcd

# format
test_str = 'Hello %(name)s! Welcome to %(addr)s'
d = {'name':'Tom', 'addr':'our home'}
test_str % d

test_str = 'Hello {name}! Welcome to {addr} {0}'
test_str.format('^^', name='Tom', addr='our home')

2.文字列置換

a = 'hello word'
b = a.replace('word','python')
print b # hello python

import re
a = 'hello word'
strinfo = re.compile('word')
b = strinfo.sub('python',a)
print b # hello python

3.文字列の反転

a = 'abcd'
b = a[::-1]##[::-1]      
print b

b = list(a)
b.reverse()
''.join(b)

4.コード化

a = '  '
b = 'python'
print a.decode('utf-8').encode('gbk')##decode         unicode  ，    encode               
print b.decode('utf-8')##decode         unicode  

5.分割

a='hello world'
b = a.split() # ['hello', 'world']