第3章 使用字符串；
format="Hello, %s,%s enough for ya?"
values=('world','hot')
print format % values
C:\Python27\python.exe C:/Users/Administrator/PycharmProjects/untitled1/a4.py
Hello, world,hot enough for ya?
Process finished with exit code 0
format="Hello, %s,%s,%%s enough for ya?"
values=('world','hot')
print format % values
C:\Python27\python.exe C:/Users/Administrator/PycharmProjects/untitled1/a4.py
Hello, world,hot,%s enough for ya?
Process finished with exit code 0
format="Pi wit three decimals:%.5f"
from math import pi
print format % pi
format="Pi wit three decimals:%.5f"
print format % 3.2555455454
C:\Python27\python.exe C:/Users/Administrator/PycharmProjects/untitled1/a4.py
Pi wit three decimals:3.25555
Process finished with exit code 0
如果要格式化实数(浮点数),可以使用f说明类型,同样提供所需要的精度:
一个句点在加上希望保留的小数位数。
substitute 变量替换:
from string import Template
s=Template('$x,glorious $x!')
print s.substitute(x='slurm')
C:\Python27\python.exe C:/Users/Administrator/PycharmProjects/untitled1/a4.py
slurm,glorious slurm!
如果替换字段是单词的一部分,那么参数名就必须用括号括起来,从而准确指明结尾:
from string import Template
s=Template("It's ${x}tastic!")
print s.substitute(x='slurm')
C:\Python27\python.exe C:/Users/Administrator/PycharmProjects/untitled1/a4.py
It's slurmtastic!
3.3 字符串格式化:完整版:
>>> '%s plus %s equals %s' %(1,2,3)
'1 plus 2 equals 3'
（1） %字符:标记转换说明符的开始
(2) 转换标志
3.4 字符串方法:
3.4.1 find 方法:
find 方法可以在一个较长的字符串中查找字符串,它返回子串所在的位置的最左端索引。
如果没有找到则返回-1
title="Money Python's Flying Circus"
print title.find('Money');
C:\Python27\python.exe C:/Users/Administrator/PycharmProjects/untitled1/a4.py
0
3.4.2 join方法:
seq=['1','2','3','4','5']
sep='+'
print sep.join(seq)
C:\Python27\python.exe C:/Users/Administrator/PycharmProjects/untitled1/a4.py
1+2+3+4+5
3.4.3 lower:
print 'Trondheim Hammer Dance'.lower()
C:\Python27\python.exe C:/Users/Administrator/PycharmProjects/untitled1/a4.py
trondheim hammer dance
3.4.4 replace
x='this is a test'
print x.replace('is','eez')
3.4.5 split:
这是一个非常重要的字符串方法,它是join的逆方法,用来将字符串分隔成序列
x='1,2,3,4,5'
print x.split('+')
C:\Python27\python.exe C:/Users/Administrator/PycharmProjects/untitled1/a4.py
['1,2,3,4,5']
3.4.6 strip:
strip 方法返回去除两侧(不包含内部)空格的字符串:
x=' dadad'
print x.strip()
C:\Python27\python.exe C:/Users/Administrator/PycharmProjects/untitled1/a4.py
dadad
注意:/*********字符串也是一个对象
