How to declare many variables?

Here is the letters:

letters='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'

I made a list of it with this:

chars=[]
for i in letters:
  chars.append(i)

So I have a chars list.

I need to all variables=0 each one to declare. And I wrote that:

for i in chars:
  chars[i]=0;

But there is an error message, like this:

Traceback (most recent call last):
  File "python", line 15, in <module>
TypeError: list indices must be integers or slices, not str

The question: How to declare these multiple variables?

You can use either a list of tuples or a dict. A simple solution to do it:

>>> import string
>>> letters = string.ascii_uppercase + string.ascii_lowercase + string.digits
>>> chars = dict.fromkeys(letters , 0)
>>> chars
>>> {...'a': 0, 'b': 0 ....}

To use list of tuples:

>>> list(chars.items())
>>> [...('a',0), ('b', 0)...]

The Solution

So, in short, what you want is a dictionary (mapping) of character -> 0 for each character in the input.

This is the way to do it:

letters='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'
chars = {char: 0 for char in letters}

The Problem

The problem with the original code was that there, chars was a list (because it was created as a list here: chars=[]), and characters were used as its indices.

So, the first time chars[i]=0; was executed (BTW, ; is not needed here), i was 'A' and chars['A']=0 produces the error.

An alternative to list comprehensions is to use map

In [841]: letters='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'

In [842]: chars = list(map(lambda l: 0, letters))

Or if you want a dict like the other answers are suggesting

In [844]: dict(map(lambda l: (l, 0), letters))

I generally find list/dict comprehensions to both be faster and more readable (to me at least). This is just a different approach