如何在Lambda，Python中保存索引

Question

I'm trying to do the following:

>>>func = lambda string,i=0: string[index]

>>> func('HEY')
H
>>> func('HEY')
E
>>> func('HEY')
Y

How can i save and increment index each time(without creating index as global) thanks

Answer 1

Solution 1

You can create a generator function, like this

def get_next_char(actual_string):
    for char in actual_string:
        yield char

Then, you need to create a generator object, like this

next_char = get_next_char("HEY")

That's it. You can now get the next character with next function, like this

>>> next(next_char)
H
>>> next(next_char)
E
>>> next(next_char)
Y

Solution 2

You can simply use the String's iterator, like this

get_char = iter("HEY")
>>> next(get_char)
H
>>> next(get_char)
E
>>> next(get_char)
Y