将文本文件转换为字典

Question

I have a text file called dict1.txt that contains two lines and I'd like to make the first string to give the keys and the second to give the values. The text file is

abcdefghijklmnopqrstuvwxyz

gikaclmnqrpoxzybdefhjstuvw

and the code I've been toying with is:

def read_cipherdef(fn):
d = {}
fn = open('dict1.txt', 'r')
for line in fn:
    key, val = line.split()
    d[(key)] = val

but in this case line.split() doesn't actually split the first line by character and it also gives a ValueError: too many values to unpack (expected 2).

Also I'm aware list(map(''.join, zip(*[iter('dict1.txt')]*1))) would split them up individually, but using that in conjunction with the existing code gives me another ValueError. So my question would be: how would I use all of this info here together to achieve my desired dictionary?

Thanks.

Answer 1

Here's one way you can achieve that. Essentially, read the two lines, zip them and use them in a dict-comprehension.

>>> with open("/tmp/t") as f:
...     line1 = f.readline().strip()
...     line2 = f.readline().strip()
...     print({x:y for x, y in zip(line1, line2)})
... 
{'a': 'g', 'b': 'i', 'c': 'k', 'd': 'a', 'e': 'c', 'f': 'l', 'g': 'm', 'h': 'n', 'i': 'q', 'j': 'r', 'k': 'p', 'l': 'o', 'm': 'x', 'n': 'z', 'o': 'y', 'p': 'b', 'q': 'd', 'r': 'e', 's': 'f', 't': 'h', 'u': 'j', 'v': 's', 'w': 't', 'x': 'u', 'y': 'v', 'z': 'w'}

.. Or if you want a one-liner (this assumes there are only 2 lines in the file):

>>> with open("/tmp/t") as f:
...     print({x: y for x, y in zip(*[list(x.strip()) for x in f])})
... 
{'a': 'g', 'b': 'i', 'c': 'k', 'd': 'a', 'e': 'c', 'f': 'l', 'g': 'm', 'h': 'n', 'i': 'q', 'j': 'r', 'k': 'p', 'l': 'o', 'm': 'x', 'n': 'z', 'o': 'y', 'p': 'b', 'q': 'd', 'r': 'e', 's': 'f', 't': 'h', 'u': 'j', 'v': 's', 'w': 't', 'x': 'u', 'y': 'v', 'z': 'w'}

Answer 2

How about this?

with open('dict1.txt') as f:
    lines=[line.strip('\n') for line in f.readlines()]
    d=dict(zip(lines[0],lines[1]))

from pprint import pprint
pprint(d)

Result:

{'a': 'g',
 'b': 'i',
 'c': 'k',
 'd': 'a',
 'e': 'c',
 'f': 'l',
 'g': 'm',
 'h': 'n',
 'i': 'q',
 'j': 'r',
 'k': 'p',
 'l': 'o',
 'm': 'x',
 'n': 'z',
 'o': 'y',
 'p': 'b',
 'q': 'd',
 'r': 'e',
 's': 'f',
 't': 'h',
 'u': 'j',
 'v': 's',
 'w': 't',
 'x': 'u',
 'y': 'v',
 'z': 'w'}

Answer 3

You can, also, do it like this way:

data = (k.rstrip() for k in open("dict1.txt", 'r'))
a = {k:v for k,v in zip(*data)}
print(a)

Or maybe in one line:

a = {k:v for k,v in zip(*(k.rstrip() for k in open("dict1.txt", 'r')))}
print(a)

Output:

{'a': 'g', 'y': 'v', 'k': 'p', 'j': 'r', 'f': 'l', 'g': 'm', 'o': 'y', 'r': 'e', 's': 'f', 'b': 'i', 'e': 'c', 'u': 'j', 't': 'h', 'z': 'w', 'l': 'o', 'c': 'k', 'h': 'n', 'i': 'q', 'n': 'z', 'd': 'a', 'w': 't', 'x': 'u', 'v': 's', 'm': 'x', 'p': 'b', 'q': 'd'}

Answer 4

Instead of the comprehension you can use dict directly:

dict(zip(*open('dict1.txt', 'rt').read().strip().split()))

Output:

{'a': 'g', 'b': 'i', 'c': 'k', 'd': 'a', 'e': 'c', 'f': 'l', 'g': 'm', 'h': 'n', 'i': 'q', 'j': 'r', 'k': 'p', 'l': 'o', 'm': 'x', 'n': 'z', 'o': 'y', 'p': 'b', 'q': 'd', 'r': 'e', 's': 'f', 't': 'h', 'u': 'j', 'v': 's', 'w': 't', 'x': 'u', 'y': 'v', 'z': 'w'}