Generate a random letter in Python

Question

Is there a way to generate random letters in Python (like random.randint but for letters)? The range functionality of random.randint would be nice but having a generator that just outputs a random letter would be better than nothing.

Wive

Answer 1

Simple:

>>> import string
>>> string.ascii_letters
'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
>>> import random
>>> random.choice(string.ascii_letters)
'j'

string.ascii_letters returns a string containing the lower case and upper case letters according to the current locale.

random.choice returns a single, random element from a sequence.

Ingenue

It's actually string.ascii_lowercase or string.ascii_uppercase. – Deuterium

Often, I need a string of randoms, here's that (after from string import ascii_letters, digits and from random import choice): ''.join([choice(ascii_letters + digits) for i in range(32)]) – Tortious

@joaquin string.letters is present in python 2.7.7. – Senseless

Answer 2

>>> import random
>>> import string
>>> random.choice(string.ascii_letters)
'g'

Laskowski

This can be lower or uppercase. Not sure if that is what is needed. – Deuterium

@TaylorLeese, as I have known that there are three options including ascii_letters, ascii_uppercase, and ascii_lowercase. – Sellma

Answer 3

>>>def random_char(y):
       return ''.join(random.choice(string.ascii_letters) for x in range(y))

>>>print (random_char(5))
>>>fxkea

to generate y number of random characters

Eyla

also: ''.join(random.sample(string.ascii_lowercase,5)) – Dreamadreamer

@Dreamadreamer Doesn't random.sample() return a unique set of values from the input, which is not the same as random.choice()? – Bareback

Yes, though if you're choosing just one letter that doesn't make a difference Furthermore, you may want 5 unique letters - the OP didn't specify, and both random.choice and random.randint return a single value. You can also use numpy.random.choice to give a unique set if you add replace=False, like so: numpy.random.choice(string.ascii_lowercase, size=5, replace=False) – Dreamadreamer

Oh, and y is not defined. Be careful about that. – Lithe

@Lithe y is the argument passed to the function – Eyla

@saad okay I understand you – Lithe

Answer 4

>>> import random
>>> import string    
>>> random.choice(string.ascii_lowercase)
'b'

Deuterium

Answer 5

You can use this to get one or more random letter(s)

import random
import string
random.seed(10)
letters = string.ascii_lowercase
rand_letters = random.choices(letters,k=5) # where k is the number of required rand_letters

print(rand_letters)

['o', 'l', 'p', 'f', 'v']

Bernoulli

@NigelRen what is the distribution of random.choices ? – Fitch

@SalmanLashkarara help(random.choices) states If the relative weights or cumulative weights are not specified, the selections are made with equal probability. This would mean, that the distribution is the discrete uniform distribution (en.wikipedia.org/wiki/Discrete_uniform_distribution). – Harsh

Answer 6

Another way, for completeness:

>>> chr(random.randrange(97, 97 + 26))

Use the fact that ascii 'a' is 97, and there are 26 letters in the alphabet.

When determining the upper and lower bound of the random.randrange() function call, remember that random.randrange() is exclusive on its upper bound, meaning it will only ever generate an integer up to 1 unit less that the provided value.

Joellyn

That depends on what alphabet we're talking about ;-) – Vannavannatta

shouldn't it be chr(random.randrange(97, 97 + 26 - 1))? – Lakshmi

@Lakshmi Really, it should be chr(random.randrange(97, 97 + 26). random.randrange() is exclusive on its upper bound, meaning that in order to get the whole range of characters 97 - 122, the argument passed must be 123. – Dirkdirks

@KieranMoynihan Thanks for sharing. I double checked that and you're right. Now I see why 97 + 26 is used. – Lakshmi

Answer 7

You can just make a list:

import random
list1=['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h']
b=random.randint(0,7)
print(list1[b])

Bidle

Answer 8

This doesn't use any fancy modules but works fine:

    ''.join(chr(random.randrange(65,90)) for i in range(10))

Agglomerate

Answer 9

def randchar(a, b):
    return chr(random.randint(ord(a), ord(b)))

Ecbolic

Answer 10

import random
def guess_letter():
    return random.choice('abcdefghijklmnopqrstuvwxyz')

Popp

Answer 11

And another, if you pefer numpy over random:

import numpy as np
import string
np.random.choice(list(string.ascii_letters))

Desolate

Answer 12

import random
def Random_Alpha():
    l = ['A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z']
    return l[random.randint(0,25)]

print(Random_Alpha())

Anlace

Answer 13

#*A handy python password generator*

here is the output

 import random
    letters = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']
    numbers = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
    symbols = ['!', '#', '$', '%', '&', '(', ')', '*', '+']
        
    print("Welcome to the Python Password Generator!")
    l= int(input("How many letters would you like in your password?\n")) 
    s = int(input(f"How many symbols would you like?\n"))
    n = int(input(f"How many numbers would you like?\n"))
        
    sequence = random.sample(letters,l)
    num      = random.sample(numbers,n)
    sym      = random.sample(symbols,s)
    sequence.extend(num)
    sequence.extend(sym)
         
    random.shuffle(sequence)
    password = ''.join([str(elem) for elem in sequence])#listToStr 
    print(password)

Samite

Answer 14

You can use

map(lambda a : chr(a),  np.random.randint(low=65, high=90, size=4))

Councilor

Answer 15

A summary and improvement of some of the answers.

import numpy as np
n = 5
[chr(i) for i in np.random.randint(ord('a'), ord('z') + 1, n)]
# ['b', 'f', 'r', 'w', 't']

Dividers

Answer 16

import string
import random

KEY_LEN = 20

def base_str():
    return (string.letters+string.digits)   
def key_gen():
    keylist = [random.choice(base_str()) for i in range(KEY_LEN)]
    return ("".join(keylist))

You can get random strings like this:

g9CtUljUWD9wtk1z07iF
ndPbI1DDn6UvHSQoDMtd
klMFY3pTYNVWsNJ6cs34
Qgr7OEalfhXllcFDGh2l

Unsteel

1. With Python3, it would be string.ascii_letters 2. You can save the list comprehension by using keylist = random.choices(base_str(), k=KEY_LEN) 3. Why having base_str as a function and not a base_str = string.ascii_letters+string.digits? – Harsh

Answer 17

def create_key(key_len):
    key = ''
    valid_characters_list = string.letters + string.digits
    for i in range(key_len):
        character = choice(valid_characters_list)
        key = key + character
    return key

def create_key_list(key_num):
    keys = []
    for i in range(key_num):
        key = create_key(key_len)
        if key not in keys:
            keys.append(key)
    return keys

Animalist

Answer 18

All previous answers are correct, if you are looking for random characters of various types (i.e. alphanumeric and special characters) then here is an script that I created to demonstrate various types of creating random functions, it has three functions one for numbers, alpha- characters and special characters. The script simply generates passwords and is just an example to demonstrate various ways of generating random characters.

import string
import random
import sys

#make sure it's 3.7 or above
print(sys.version)

def create_str(str_length):
    return random.sample(string.ascii_letters, str_length)

def create_num(num_length):
    digits = []
    for i in range(num_length):
        digits.append(str(random.randint(1, 100)))

    return digits

def create_special_chars(special_length):
    stringSpecial = []
    for i in range(special_length):
        stringSpecial.append(random.choice('!$%&()*+,-.:;<=>?@[]^_`{|}~'))

    return stringSpecial

print("how many characters would you like to use ? (DO NOT USE LESS THAN 8)")
str_cnt = input()
print("how many digits would you like to use ? (DO NOT USE LESS THAN 2)")
num_cnt = input()
print("how many special characters would you like to use ? (DO NOT USE LESS THAN 1)")
s_chars_cnt = input()
password_values = create_str(int(str_cnt)) +create_num(int(num_cnt)) + create_special_chars(int(s_chars_cnt))

#shuffle/mix the values
random.shuffle(password_values)

print("generated password is: ")
print(''.join(password_values))

Result:

Niko

Answer 19

Example of generating letters and numbers together

import random
import string

for_seed = random.randint(1,1000)
random.seed(for_seed)

def create_alphanumerical_randomly(n):
    
    my_letters = string.ascii_lowercase
    my_rand_letters = random.choices(my_letters, k=n)

    my_string = ""
    for letter in my_rand_letters:
        my_string += letter

    return my_string + str(for_seed)

my_func = create_alphanumerical_randomly(3)
print(my_func)

Doorpost

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Answer 20

well, this is my answer! It works well. Just put the number of random letters you want in 'number'... (Python 3)

import random

def key_gen():
    keylist = random.choice('abcdefghijklmnopqrstuvwxyz')
    return keylist

number = 0
list_item = ''
while number < 20:
    number = number + 1
    list_item = list_item + key_gen()

print(list_item)

Esophagitis

Answer 21

import string
import random

def random_char(y):
    return ''.join(random.choice(string.ascii_letters+string.digits+li) for x in range(y))
no=int(input("Enter the number of character for your password=  "))
li = random.choice('!@#$%^*&( )_+}{')
print(random_char(no)+li)

Confront

Answer 22

My overly complicated piece of code:

import random

letter = (random.randint(1,26))
if letter == 1:
   print ('a')
elif letter == 2:
    print ('b')
elif letter == 3:
    print ('c')
elif letter == 4:
    print ('d')
elif letter == 5:
    print ('e')
elif letter == 6:
    print ('f')
elif letter == 7:
    print ('g')
elif letter == 8:
    print ('h')
elif letter == 9:
    print ('i')
elif letter == 10:
    print ('j')
elif letter == 11:
    print ('k')
elif letter == 12:
    print ('l')
elif letter == 13:
    print ('m')
elif letter == 14:
    print ('n')
elif letter == 15:
    print ('o')
elif letter == 16:
    print ('p')
elif letter == 17:
    print ('q')
elif letter == 18:
    print ('r')
elif letter == 19:
    print ('s')
elif letter == 20:
    print ('t')
elif letter == 21:
    print ('u')
elif letter == 22:
    print ('v')
elif letter == 23:
    print ('w')
elif letter == 24:
    print ('x')
elif letter == 25:
    print ('y')
elif letter == 26:
    print ('z')

It basically generates a random number out of 26 and then converts into its corresponding letter. This could defiantly be improved but I am only a beginner and I am proud of this piece of code.

Rosado

your answer needs improvement and is not very functional. – Niko

in your case you can simply do print(chr(96 + letter)), no if-elif hell is needed – Maugham

This is if-else hell, It is not a good practice – Provost

Answer 23

Maybe this can help you:

import random
for a in range(64,90):
    h = random.randint(64, a)
    e += chr(h)
print e

Syrupy

Why are you iterating between 64 and 90? Why not just go from 0 to 26, and offset a? This answer is quite poor, the output hardly random: @AAADCCEHFGJLDJF@EHFMHKWUR – Ariel

Answer 24

Place a python on the keyboard and let him roll over the letters until you find your preferd random combo Just kidding!

import string #This was a design above but failed to print. I remodled it.
import random
irandom = random.choice(string.ascii_letters) 
print irandom

Smoothen

Welcome to Stack Overflow! While this is a good answer it is identical to the already posted and accepted answer by @MarkRushakoff, answered two years ago. Please review the answers before you post so we can keep the signal to noise ratio down. – Foin