如何在字符串中引入错字？

Question

I would like to introduce typos in a string. I have a parameter typo_prob which would flip a character in a string with a probability of typo_prob.

For example, if typo_prob is 0.1, every tenth character will be replaced by a random character.

So far I am doing this:

message = "Where do you live?"
message = list(message)
n_chars_to_flip = round(len(message) * typo_prob)
pos_to_flip = []
for i in range(n_chars_to_flip):
    pos_to_flip.append(random.randint(0, len(message) - 1))
for pos in pos_to_flip:
    message[pos] = random.choice(string.ascii_lowercase)
message = ''.join(message)

Please let me know if there is a more elegant or efficient way to do this.

Answer 1

I'd to this as following:

[x if random.random() >= 0.5 else random.choice(string.ascii_lowercase) for x in list(message)]

0.5 is the probabilty the character is replaced.

Answer 2

import random
import string

message = "Where do you live?"
message = list(message)

for pos, char in enumerate(message):
    message[pos] = random.choice(string.ascii_lowercase) if random.random() < 0.1 else char

message = "".join(message)