Detailed description of several methods of strings in python

字符串格式化

>>> '%s plus %s equals %s' % (1,1,2)
'1 plus 1 equals 2'

字段的宽度和精度

*字段宽度是转换后的值所保留的最小字符个数，精度（对于数字）是包含的小数位数，或者（对于字符）转换后的值所能包含的最大字符数

>>> from math import pi
>>> '%10f' % pi
'  3.141593'
>>> from math import pi
>>> '%10f' % pi  #字段宽10
'  3.141593'
>>> '%10.2f' % pi #字段宽10，精度2
'      3.14'
>>> '%.2f' % pi #精度2
'3.14'
>>> '%.5s' % 'My name is ningsi'
'My na'
>>> '%.*s' % (5,'My name is ningsi')
'My na'

符号、对齐和0填充

>>> '%010.2f' % pi #用0填充
'0000003.14'    
>>> '%-10.2f' % pi #左对齐
'3.14      '
>>> print ('% 5d' % 10)+'\n'+('%5d' % -10)
   10
  -10
>>> print ('%+5d' % 10)+'\n'+('%+5d' % -10)
  +10
  -10

 

字符串的方法

find 查找子字符串

>>> N='ning si de shu de'>>> N.find('de')8
>>> N.find('dee')-1
>>> N.find('de',9,16) #范围包含第一个索引不包含第二个-1

 

join 是split方法的逆方法

>>> s=['1','2','3','4']
>>> q.join(s)
'1+2+3+4'
>>> p='','usr','bin','env'
>>> '/'.join(p)
'/usr/bin/env'>>> print 'C:'+'\\'.join(p)
C:\usr\bin\env

lower 返回字符串的小写字母版

>>> 'My name is ningsideshu'.lower()
'my name is ningsideshu'
>>> if 'name' in ['my','Name','is']:print 'Found it!'

>>> if 'my' in ['my','Name','is']:print 'Found it!'

Found it!

replace 替换

>>> 'This is a pen'.replace('pen','apple')'This is a apple'

split 将字符串分割成序列

>>> '1+2+3+4+5'.split('+')
['1', '2', '3', '4', '5']
>>> '/usr/bin/env'.split('/')
['', 'usr', 'bin', 'env']
>>> 'Using the default'.split() #默认所有空格作为分隔符（空格、换行等）
['Using', 'the', 'default']

strip 返回去除两侧空格（或指定字符）的字符串 (另外：lstrip,rstrip)

>>> ' My name is Nsds  '.strip()'My name is Nsds'>>> ' *My name is Nsds * '.strip(' *')'My name is Nsds'

translate 替换，与replace不同的是，可以替换单个字符（字符串中的某些部分）

>>> from string import maketrans
>>> N=maketrans('ns','mf')
>>> 'My name is ningsideshu'.translate(N)
'My mame if mimgfidefhu'
>>> 'My name is ningsideshu'.translate(N,'M') #第二个参数指定需要删除的字符
'y mame if mimgfidefhu'

模版字符串

>>> from string import Template
>>> s=Template('$x. name $x!')
>>> s.substitute(x='hello')
'hello. name hello!'
>>> s=Template("It't ${x}tastic!")
>>> s.substitute(x='slurm')
"It't slurmtastic!"
>>> s=Template("It't ${x}tastic${y}!")
>>> s.substitute(x='slurm',y='a')
"It't slurmtastica!"
>>> s=Template('A $thing must never $action.') 
>>> d={}
>>> d['thing']='gentleman'
>>> d['action']='show his socks'
>>> s.substitute(d)
'A gentleman must never show his socks.'

 

The above is the detailed content of Detailed description of several methods of strings in python. For more information, please follow other related articles on the PHP Chinese website!