Condense list into string : ['z','y','x'...] -> 'zyx...' ? Python (2.7.1)

Question

If I have list='abcdedcba'

and i want: a=z, b=y, c=x, d=w, e=v so it would translate to:

translate='zyxwvwxya'

How would I do this? If I construct a dictionary

>>> d=dict(zip(('a','b','c','d','e'),('z','y','x','w','v')))

and type

>>> example= d[x] for x in list
>>> print translate
['z', 'y', 'x', 'w', 'v', 'w', 'x', 'y', 'z']

How do I get it back into the form

translate='zyxwvwxyz'

?

score 12 · Accepted Answer · answered Apr 20 '11 at 05:24

12

the_list = ['z', 'y', 'x', 'w', 'v', 'w', 'x', 'y', 'z']
print "".join(the_list)

answered Apr 20 '11 at 05:24

eat_a_lemon

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score 5 · Answer 2 · answered Apr 20 '11 at 05:43

5

For monoalphabetic substitution, use maketrans and translate from the string module. They operate like the unix tr command. Joining with an empty separator is the correct answer for that last step, but not necessary for this exact task.

answered Apr 20 '11 at 05:43

Yann Vernier

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score 2 · Answer 3 · answered Apr 20 '11 at 05:25

2

''.join(translate)

I'm not sure this is what you want?

answered Apr 20 '11 at 05:25

jcomeau_ictx

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gurney alex · Answer 4 · 2011-04-22T07:32:55.423

2

an example of using maketrans and translate:

>>> import string
>>> table = string.maketrans('abcdef', 'zyxwvu')
>>> 'abdedddfdffdabe'.translate(table)
'zywvwwwuwuuwzyv'

Assuming you want to substitute all letters in the ASCII alphabet:

import string
reversed_ascii_letters = string.ascii_letters[::-1]
# reorder lowercase and uppercase
reversed_ascii_letters = reversed_ascii_letters[26:] + reversed_ascii_letters[:26]
table = string.maketrans(string.ascii_letters, reversed_ascii_letters)
data = 'The Quick Brown Fox Jumped Over the Lazy Dog'
print data.translate(table)

edited Apr 22 '11 at 07:32

answered Apr 20 '11 at 06:00

gurney alex

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`'abdedddfdffdabe'` has the `translate()` method, so you can just use `'abdedddfdffdabe'.translate(table)` – John La Rooy Apr 20 '11 at 06:32
so with this i could just skip the dictionary step? – O.rka Apr 20 '11 at 17:48

score 1 · Answer 5 · answered Apr 20 '11 at 06:31

1

>>> import string
>>> table = string.maketrans(string.lowercase, string.lowercase[::-1])
>>> 'abcdedcba'.translate(table)
'zyxwvwxyz'

answered Apr 20 '11 at 06:31

John La Rooy

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score 0 · Answer 6 · answered Apr 20 '11 at 10:17

>>> import string
>>> letters = string.lowercase
>>> letters
'abcdefghijklmnopqrstuvwxyz'
>>> def revert_string(s):
    s_rev = ''
    for c in s:
        s_rev += letters[len(letters) - 1 - letters.find(c)]
    return s_rev

>>> s = 'zearoizuetlkzjetkl'
>>> revert_string(s)
'avzilrafvgopaqvgpo'

Condense list into string : ['z','y','x'...] -> 'zyx...' ? Python (2.7.1)

6 Answers6