Python：循环完成后对字母表

Question

I tried to pair Alphabets by this

import string
a=string.uppercase
for i in range(0,30):
    print a[i%26]*(i / 26+1)

This will print A-Z and then after Z it will print AA BB like string

but i need to put this string like AA AB AC AD AE until the range is defined after printing AZ then the result will be like print AZ then AA AB AC ....

Answer 1

You can take advantage of the itertools module and use a generator to handle this pretty cleanly:

from itertools import count, product, islice
from string import ascii_uppercase

def multiletters(seq):
    for n in count(1):
        for s in product(seq, repeat=n):
            yield ''.join(s)

gives

>>> list(islice(multiletters('ABC'), 20))
['A', 'B', 'C', 'AA', 'AB', 'AC', 'BA', 'BB', 'BC', 'CA', 'CB', 'CC', 'AAA', 'AAB', 'AAC', 'ABA', 'ABB', 'ABC', 'ACA', 'ACB']
>>> list(islice(multiletters(ascii_uppercase), 30))
['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'AA', 'AB', 'AC', 'AD']

and you can make an object and get them one by one, if you'd prefer:

>>> m = multiletters(ascii_uppercase)
>>> next(m)
'A'
>>> next(m)
'B'
>>> next(m)
'C'

[Update: I should note though that I pass data between Python and Excel all the time -- am about to do so, actually -- and never need this function. But if you have a specific question about the best way to exchange data, it's probably better to ask a separate question than to edit this one now that there are several answers to the current question.]

Answer 2

I think what you are looking for is a nested for loop, like this:

import string

def get_string(val):
    return string.uppercase[val%26]*(val / 26+1)


for i in range(0,26):
    for j in range(0, 26):
        print get_string(i) + get_string(j)

Note that I defined your indexing of string.uppercase to a function ( get_string ) so that its code would not be repeated.

Answer 3

I think what you want is something like this

import string

def get_string(val):
    return string.uppercase[val%26]*(val / 26+1)


for i in range(-1,26):
    for j in range(0, 26):
        if i==-1:
            print get_string(j)
        else:
            print get_string(i) + get_string(j)

The first time through the outer loop, do not print a leading character (the first 26 Excel columns) then after that the next 26 columns print a letter followed by a second letter.

Working example available on ideone.com -> http://ideone.com/M862Ra