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[英]What is the best way to generate all binary strings of the given length in Python using Recursion?
[英]What's the best way to generate random strings of a specific length in Python?
對於一個項目,我需要一種創建數千個隨機字符串同時保持低沖突的方法。 我正在尋找它們只有 12 個字符長且僅大寫。 有什么建議么?
代碼:
from random import choice
from string import ascii_uppercase
print(''.join(choice(ascii_uppercase) for i in range(12)))
輸出:
5個例子:
QPUPZVVHUNSN
EFJACZEBYQEB
QBQJJEEOYTZY
EOJUSUEAJEEK
QWRWLIWDTDBD
編輯:
如果您只需要數字,請使用digits
常量而不是string
模塊中的ascii_uppercase
之一。
3個例子:
229945986931
867348810313
618228923380
通過Django
,您可以在django.utils.crypto
模塊中使用get_random_string
函數。
get_random_string(length=12,
allowed_chars=u'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789')
Returns a securely generated random string.
The default length of 12 with the a-z, A-Z, 0-9 character set returns
a 71-bit value. log_2((26+26+10)^12) =~ 71 bits
例子:
get_random_string()
u'ngccjtxvvmr9'
get_random_string(4, allowed_chars='bqDE56')
u'DDD6'
但是如果你不想擁有Django
, 這里是它的獨立代碼:
代碼:
import random
import hashlib
import time
SECRET_KEY = 'PUT A RANDOM KEY WITH 50 CHARACTERS LENGTH HERE !!'
try:
random = random.SystemRandom()
using_sysrandom = True
except NotImplementedError:
import warnings
warnings.warn('A secure pseudo-random number generator is not available '
'on your system. Falling back to Mersenne Twister.')
using_sysrandom = False
def get_random_string(length=12,
allowed_chars='abcdefghijklmnopqrstuvwxyz'
'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'):
"""
Returns a securely generated random string.
The default length of 12 with the a-z, A-Z, 0-9 character set returns
a 71-bit value. log_2((26+26+10)^12) =~ 71 bits
"""
if not using_sysrandom:
# This is ugly, and a hack, but it makes things better than
# the alternative of predictability. This re-seeds the PRNG
# using a value that is hard for an attacker to predict, every
# time a random string is required. This may change the
# properties of the chosen random sequence slightly, but this
# is better than absolute predictability.
random.seed(
hashlib.sha256(
("%s%s%s" % (
random.getstate(),
time.time(),
SECRET_KEY)).encode('utf-8')
).digest())
return ''.join(random.choice(allowed_chars) for i in range(length))
可以做一個生成器:
from string import ascii_uppercase
import random
from itertools import islice
def random_chars(size, chars=ascii_uppercase):
selection = iter(lambda: random.choice(chars), object())
while True:
yield ''.join(islice(selection, size))
random_gen = random_chars(12)
print next(random_gen)
# LEQIITOSJZOQ
print next(random_gen)
# PXUYJTOTHWPJ
然后在需要它們時從生成器中提取它們......當你需要它們時使用next(random_gen)
,或者使用random_200 = list(islice(random_gen, 200))
例如......
此函數生成具有指定長度的隨機大寫字母字符串,
eg: length = 6,會生成如下隨機序列模式
YLNYVQ
import random as r
def generate_random_string(length):
random_string = ''
random_str_seq = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
for i in range(0,length):
if i % length == 0 and i != 0:
random_string += '-'
random_string += str(random_str_seq[r.randint(0, len(random_str_seq) - 1)])
return random_string
#!/bin/python3
import random
import string
def f(n: int) -> str:
bytes(random.choices(string.ascii_uppercase.encode('ascii'),k=n)).decode('ascii')
對於非常大的 n 跑得更快。 避免 str 連接。
一個沒有重復的隨機生成器函數,使用set
來存儲之前生成的值。 請注意,這將花費一些內存非常大的字符串或數量,並且可能會減慢一點。 generator
將在給定數量或達到最大可能組合時停止。
代碼:
#!/usr/bin/env python
from typing import Generator
from random import SystemRandom as RND
from string import ascii_uppercase, digits
def string_generator(size: int = 1, amount: int = 1) -> Generator[str, None, None]:
"""
Return x random strings of a fixed length.
:param size: string length, defaults to 1
:type size: int, optional
:param amount: amount of random strings to generate, defaults to 1
:type amount: int, optional
:yield: Yield composed random string if unique
:rtype: Generator[str, None, None]
"""
CHARS = list(ascii_uppercase + digits)
LIMIT = len(CHARS) ** size
count, check, string = 0, set(), ''
while LIMIT > count < amount:
string = ''.join(RND().choices(CHARS, k=size))
if string not in check:
check.add(string)
yield string
count += 1
for my_count, my_string in enumerate(string_generator(12, 20)):
print(my_count, my_string)
輸出:
0 IESUASWBRHPD
1 JGGO1THKLC9K
2 BW04A5GWBA7K
3 KDQTY72BV1S9
4 FAOL5L28VVMN
5 NLDNNBGHTRTI
6 2RV6TE6BCQ8K
7 B79B8FBPUD07
8 89VXXRHPUN41
9 DFC8QJUY6HRB
10 FXYYDKVQHC5Z
11 57KTZE67RSCU
12 389H1UT7N6CI
13 AKZMN9XITAVB
14 6T9ACH3GDAYG
15 CH8RJUQMTMBE
16 SPQ7E02ZLFD3
17 YD6JFXGIF3YF
18 ZUSA2X6OVNCN
19 JQRH6LR229Y4
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