python基础5--字符串

s = "this apple is red apple"
s.find("apple")
s.find("apple",9)
s.find("apple",1,3) 
s.rfind("app") #从字符串尾部向前查找
s.index("pp")
s.count("p")

s.split(' ') #使用空格分割 ['this', 'apple', 'is', 'red', 'apple']
s.partition(' ')  #('this', ' ', 'apple is red apple')

s1 = s.split(' ')
sep = "-"
s2 = sep.join(s1) #'this-apple-is-red-apple'

s.replace("apple","orange") #'this orange is red orang'

import string
table = string.maketrans("abcdefg","1234567")
s = "this apple is red apple"
s.translate(table) #'this 1ppl5 is r54 1ppl5'
s.translate(table,"hijk") #删除hijk  'ts 1ppl5 s r54 1ppl5'

s = "  abc   "
s.strip() #删除两端空白字符 'abc'
"abdc".strip("a") #删除指定字符
"aabdcaaa".rstrip("a") #删除右端指定字符  'aabdc'

eval("3+4")
import math
eval('math.sqrt(3)')