How can I save the results in a text file?

What I tried is to search the mojang API for all available 3/4 letter usernames, but when I launch the program it just runs for like an hour or so then stops, and does not save the results in a text file, so can someone help me with saving them to a txt file to my desktop?

Code:

import re
import requests as r
import itertools
from time import sleep



def check_name(name):
    url = "https://api.mojang.com/users/profiles/minecraft/{}"
    name_url = url.format(name)
    res = r.get(name_url)


    if res.status_code == 204:
        return True
    elif res.status_code == 200:
        return False
    elif res.status_code == 429:
        sleep(5)
        return(check_name(name))

names = []
for i in itertools.product("abcdefghijklmnopqrstuvwxyz_0123456789",repeat=3):
    name = ""
    for ch in i:
        name += ch
    names.append(name)

for name in names:
    if check_name(name):
        f = open("names.txt","a")
        f.write(f"{name}\n")

I tried to rewrite the code multiple times but nothing seemed to work, I'm also new to Python do probably that's why.

Combining my two comments. There is no need to save the names in a list to just write them out in the next loop. And you can convert the tuple of chars to a string with ''.join(i). So I would replace the last two loops with

with open("names.txt","w") as fh:
    for i in itertools.product("abcdefghijklmnopqrstuvwxyz_0123456789",repeat=3):
        name = ''.join(i)
        if check_name(name):
            fh.write(name)
            fh.write("\n")
            fh.flush()

EDIT: I added fh.flush since I now realize that your check_name may take time and you want the file to correctly reflect where you are right now without delays due to buffering of the output.

Create a list save_names to store the names that are available.
Iterate through the names list, and for each name, call the check_name function to determine if it is available or not. If it is available, Add it to the save_names list. Then write the names in the available_names list to the file using the write method

import re
import requests as r
import itertools
from time import sleep

def check_name(name):
    url = "https://api.mojang.com/users/profiles/minecraft/{}"
    name_url = url.format(name)
    res = r.get(name_url)

    if res.status_code == 204:
        return True
    elif res.status_code == 200:
        return False
    elif res.status_code == 429:
        sleep(5)
        return check_name(name)

names = []
for i in itertools.product("abcdefghijklmnopqrstuvwxyz_0123456789", repeat=3):
    name = ""
    for ch in i:
        name += ch
    names.append(name)

save_names = []
for name in names:
    if check_name(name):
        save_names.append(name)

# Save results to a text file
with open("names.txt", "w") as f:
    f.write("\n".join(save_names))

I see two problems in your code, the first one is that you are considering a True case when the response is 204, which means "No content". When the status code is "OK" 200 is returned, so I modified that part. Now, the way you are using open() is not the most accurate option, cause you are not closing the file. Instead, try using context with the keyword "with"

import itertools
from time import sleep

import requests as r


def check_name(name):
    url = "https://api.mojang.com/users/profiles/minecraft/{}"
    name_url = url.format(name)
    res = r.get(name_url)

    if res.status_code == 200:
        return True
    elif res.status_code == 204:
        return False
    elif res.status_code == 429:
        sleep(5)
        return check_name(name)


names = []
for i in itertools.product("a", repeat=3):
    name = ""
    for ch in i:
        name += ch
    names.append(name)

with open("names.txt", "w") as file:
    for name in names:
        if check_name(name):
            file.write(f"{name}\n")

You can have better approaches like Nadir's suggestion, but this code has almost the same logic that in your code provided