Are you able to make a dictionary like this? (Using external .txt files)

Question

Is there an easier way of creating a dictionary on Python from a .txt file than this:

for y in open('bones.txt'):
    bones={','.join(y:'0')}

where bones.txt contains:

Ankylosaurus
Pachycephalosaurus
Ankylosaurus
Tyrannosaurus Rex
Ankylosaurus
Struthiomimus
Struthiomimus

`','.join(y:'0')` gives me a `SyntaxError` - what exactly is this line supposed to achieve? — UnholySheep, Aug 22 '18 at 12:17

Henry · Answer 1 · 2018-08-22T13:30:16.980

3

with open("bones.txt") as f:
    my_dict = dict.fromkeys(f, '0')

Thanks for the suggustions and I get this answer above.

to clean out line breaks, maybe we can use os.linesep

import os
with open("bones.txt") as f:
    my_dict = dict.fromkeys(map(lambda x: x.replace(os.linesep, ""), f), '0')

edited Aug 22 '18 at 13:30

answered Aug 22 '18 at 12:18

Henry

Sasha Tsukanov · Answer 2 · 2018-08-22T13:10:13.657

0

You can use a dict comprehension.

with open('bones.txt') as f:
    bones = { line: 0 for line in f.read().splitlines() }

str.splitlines does not include the newline character to the lines, so we don't have to strip it.

edited Aug 22 '18 at 13:10

answered Aug 22 '18 at 12:33

Sasha Tsukanov

@MadPhysicist not in my case. Can it be due to Python version/OS? I'm using Python 3.5 on Ubuntu – Sasha Tsukanov Aug 22 '18 at 12:52
@MadPhysicist Yes, I've tried, I get something like this `['q\n', 'w\n', 'e\n', 'r\n', 't\n', 'y\n', '\n']` as the output – Sasha Tsukanov Aug 22 '18 at 12:56
@MadPhysicist I think it is common https://stackoverflow.com/questions/12330522/reading-a-file-without-newlines I came to a cleaner solution with `splitlines()` – Sasha Tsukanov Aug 22 '18 at 13:12
1

@MadPhysicist the file iterator doesn't strip anything, neither in python 2.7x nor in 3.6.5, so I doubt it does in 3.5.x. – bruno desthuilliers Aug 22 '18 at 13:23

score 0 · Answer 3 · edited Aug 22 '18 at 14:06

0

This method can also be modified to include values for keys without making it too complicated:

bones = {}
for y in open('bones.txt'):
   bones[y.strip('\n')] = '0'

edited Aug 22 '18 at 14:06

Mad Physicist

answered Aug 22 '18 at 12:47

Darth_Sourav

2

Why convert something that is already a string into a string? – Mad Physicist Aug 22 '18 at 12:51
1

Why not use a with block when you really should? – Mad Physicist Aug 22 '18 at 12:52
I wanted to do it keeping Op's approach. and newline character is there to strip. for your point 1, I made the edit. Thanks. – Darth_Sourav Aug 22 '18 at 12:57
OP came here to learn. It's up to you to instruct him not to make the mistakes he's making. – Mad Physicist Aug 22 '18 at 13:02
Ideally you could include the `with`-based solution with a little comment after yours to your answer – Sasha Tsukanov Aug 22 '18 at 13:24
@SashaTsukanov The solution including `with` based solution provided by Henry yuan and Mad Physicist is more elegant. Personally I wanted to present a solution with the basic operations which gives the solution keeping Op's way of thought. – Darth_Sourav Aug 22 '18 at 15:24
@MadPhysicist can you please tell me what have you edited in my solution so I can keep that in mind for the future? – Darth_Sourav Aug 22 '18 at 15:27
1

When a vote sits for too long, you can't change it unless an edit is made to the post. I wanted to remove my downvote, so I made an edit that I considered to be harmless. If you want me to change the colon back to a period, I'd be more than happy to do it. – Mad Physicist Aug 22 '18 at 15:31
Wishing had the privilege to upvote your comment. and no, the colon is harmless. cheers. – Darth_Sourav Aug 22 '18 at 15:39

3 Answers3