python 字符串

#字符串

>>>s ="hello"

>>>s[::-1]

'olleh'

#拒绝猜的诱惑

"42" + 1 (X)

int 将字符串转换为数字，str将数字转换为字符串

float 把字符串转换成浮点数

ord('s') --- 115

chr(115) --- 's'

#修改字符串 ，不能在原处直接修改字符串

#替换一个字符串中的两个字符

(1)

>>> s = 'spammy'

>>> s = s[:3]+'xx'+s[5:]

>>> s

'spaxxy'

>>>s=s.replace('mm','xx');

>>>s

'spaxxy'

(2)

>>> S = 'xxxxSPAMxxxxSPAMxxxx'

>>> where = S.find('SPAM')

>>> where

4

>>> s = s[:where] +'EGGS' +s[(where+4):]

>>> S

'xxxxEGGSxxxxSPAMxxxx'

>>> s = 'xxxxSPAMxxxxSPAMxxxx'

>>> s.replace('SPAM','EGGS')

'xxxxEGGSxxxxEGGSxxxx'

>>> s.replace('SPAM' ,'EGGS' ,1)

'xxxxEGGSxxxxSPAMxxxx'

List可以将字符串转换成列表

join可以将列表合成一个字符串

>>> s = ''.join(L)

>>> s

#文本解析 简单的文本解析

>>> line = 'aaa bbb ccc'

>>> col1 = line[0:3]

>>> col3 = line[8:]

>>> col1

'aaa'

>>> col3

'ccc'

#1-split方法将一个字符串分割为一个字符串的列表，以分割符字符串标准

>>> line = 'bob ,hacker,40'

>>> line.split(',')

['bob' , 'hacker' ,'40']

>>> line ="i'mSPAMaSPAMlumberjack"

>>> line.split("SPAM")

["i'm",'a','lumberjack']

#2-其他方法

rstrip()

upper()

isalpha()

endswith()

startswith()