python3中maketrans()方法的使用

2019独角兽企业重金招聘Python工程师标准>>>

static str.maketrans(x[, y[, z]])

This static method returns a translation table usable for str.translate().

If there is only one argument, it must be a dictionary mapping Unicode ordinals (integers) or characters (strings of length 1) to Unicode ordinals, strings (of arbitrary lengths) or None. Character keys will then be converted to ordinals.

If there are two arguments, they must be strings of equal length, and in the resulting dictionary, each character in x will be mapped to the character at the same position in y. If there is a third argument, it must be a string, whose characters will be mapped to None in the result.

str.maketrans(x[,y[,z]])可返回用于str.translate()的转换表

如果只有一个参数，必须是一个字典
例：str.maketrans(x)

>>> d = {'a':'1','b':'2','c':'3','d':'4','e':'5','s':'6'}
>>> trantab = str.maketrans(d)
>>> st='just do it'
>>> print(st.translate(trantab))
 'ju6t 4o it'

>>> d = {'a':'123','s':'456','d':'789'}
>>> trantab = str.maketrans(d)
>>> st='just do it'
>>> print(st.translate(trantab))
ju456t 789o it

>>> d = {'a':'123','s':'456','d':None}
>>> trantab = str.maketrans(d)
>>> st='just do it'
>>> print(st.translate(trantab))
ju456t o it

如果两个参数，x,y长度必须是相等的字符串，x中每个字符将映射到y中相同位置的字符
例：str.maketrans(x,y)

>>> x = 'abcdefs'
>>> y = '1234567'
>>> st='just do it'
>>> trantab = str.maketrans(x,y)
>>> print(st.translate(trantab))
ju7t 4o it

如果三个参数，第三个参数必须是个字符串，其字符将被映射为None
例：str.maketrans(x,y,z)
 

>>> x = 'abcdefs'
	 
>>> y='1234567'

>>> z='ot'

>>> st='just do it'

>>> trantab = str.maketrans(x,y,z)

>>> print(st.translate(trantab))
	 
ju7 4 i

 

转载于:https://my.oschina.net/dapeng2010/blog/1944174