CODEWITHSUNDEEP
python
javanewbie
javanewbie

Reputation: 301

Is there a random letter generator with a range?

I was wondering if there is a random letter generator in Python that takes a range as parameter? For example, if I wanted a range between A and D? I know you can use this as a generator:

import random
import string

random.choice(string.ascii_letters)

But it doesn't allow you to supply it a range.

Upvotes: 10

Views: 14607

Answers (9)

pylang
pylang

Reputation: 44525

You can build your own letter range iterator and choose from it randomly:

import random


def letter_range(start, stop, step=1):
    """Yield a range of lowercase letters.

    Examples
    --------
    >>> list(letter_range("a", "f"))
    ['a', 'b', 'c', 'd', 'e']

    >>> list(letter_range("a", "f", step=2))
    ['a', 'c', 'e']

    """
    start = ord(start.lower())
    stop = ord(stop.lower())
    for ord_ in range(start, stop, step):
        yield chr(ord_)


letters = list(letter_range("a", "g"))
random.choice(letters)
# "e"

Upvotes: 0

Iofacture
Iofacture

Reputation: 685

Saw this and thought the algorithm I just wrote might be helpful. This generates a random uppercase ascii string of N length:

from random import randint

def generate_random_nlength_string(n):
    prandstr = [chr(randint(65,90)) for _ in range(n)]
    return ''.join(prandstr)

Upvotes: 2

Nick M.
Nick M.

Reputation: 142

Using your original way of getting a random letter you can simply make a function as such.

def getLetter(start, stop):
    letter = random.choice(string.ascii_letters)
    while letter < start and letter > stop:
        letter = random.choice(string.ascii_letters)
    return letter

Calling it like getLetter('a', 'd')

Upvotes: 1

Stefan Pochmann
Stefan Pochmann

Reputation: 28606

>>> random.choice('ABCD')
'C'

Or if it's a larger range so you don't want to type them all out:

>>> chr(random.randint(ord('I'), ord('Q')))
'O'

Upvotes: 3

Michael Aaron Safyan
Michael Aaron Safyan

Reputation: 95509

You can trivially define such a thing:

def letters_in_range(start_letter, end_letter):
   start_index = string.ascii_letters.find(start_letter)
   end_index = string.ascii_letters.find(end_letter)
   assert start_index != -1
   assert end_index != -1
   assert start_letter < end_letter
   return string.ascii_letters[start_index:end_index]

With the above:

 random.choice(letters_in_range('A', 'D'))

Upvotes: 1

Mac O&#39;Brien
Mac O&#39;Brien

Reputation: 2907

You can slice string.ascii_letters:

random.choice(string.ascii_letters[0:4])

Upvotes: 12

James
James

Reputation: 2711

String slicing would be my solution to this

random.choice(string.ascii_letters[:4])

This would randomly choose one of the first 4 letters of the alphabet. Obviously 4 could be any value.

Upvotes: 4

Ami Tavory
Ami Tavory

Reputation: 76297

The function choice takes a general sequence.

Return a random element from the non-empty sequence seq.

In particular

random.choice(['A', 'B', 'C', 'D'])

will do what you want.

You can easily generate the range programatically:

random.choice([chr(c) for c in xrange(ord('A'), ord('D')+1)])

Upvotes: 3

user3435469
user3435469

Reputation: 41

Ascii is represented with numbers, so you can random a number in the range that you prefer and then cast it to char.

Upvotes: 5

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