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Python explains how to use the current time and random numbers to generate unique numbers

巴扎黑
巴扎黑Original
2017-09-21 11:08:522241browse

This article mainly introduces Python's method of using the current time and random numbers to generate a unique number, involving Python time and random number related operation skills. Friends in need can refer to it

The examples in this article describe Python A method to generate a unique number using the current time and random numbers. Share it with everyone for your reference, the details are as follows:

It is very simple to generate the current time in Python, which is much shorter than the code in Java. For Java generation time, please refer to "Java Obtaining Current System Events System.currentTimeMillis() Method"

The specific code is as follows:


#-*-coding:utf-8-*-
import datetime
now = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
print now;

The running results are as follows, the current time is output, and the time format is according to strftime("%Y-%m-% d %H:%M:%S"), the corresponding format is as simple as the printf statement in C language.

Python can use the following statement to generate a unique random number:


import random;
print random.randint(0,100);#生成的随机整数n,其中0<=n<=100

According to this, we can use the current time , a random number generates a unique number, which is used for some occasions such as uploading files and generating files.

Considering the extreme situation, if 1000 users upload files within 1 second, there will be no conflicts. The situation is to use a random integer from the current time + 0 to 1000 to construct a random number:

The only thing worth noting is that the splicing time and string must be converted into a string before splicing, rather than adding them directly. Since Python does not have variable declarations, direct addition becomes the addition of numbers.

Also note that if the random number is randomly less than 10, a 0 should be added in front of the randomly generated number so that the number of digits generated is the same.

The specific code is as follows:


#-*-coding:utf-8-*-
import datetime;
import random;
nowTime=datetime.datetime.now().strftime("%Y%m%d%H%M%S");#生成当前时间
randomNum=random.randint(0,100);#生成的随机整数n,其中0<=n<=100
if randomNum<=10:
  randomNum=str(0)+str(randomNum);
uniqueNum=str(nowTime)+str(randomNum);
print uniqueNum;

The following Python program will use for to set 10 test cases to test the results generated within one second. The code is as follows :


#-*-coding:utf-8-*-
import datetime;
import random;
for i in range (0,10):
  nowTime=datetime.datetime.now().strftime("%Y%m%d%H%M%S");#生成当前时间
  randomNum=random.randint(0,100);#生成的随机整数n,其中0<=n<=100
  if randomNum<=10:
    randomNum=str(0)+str(randomNum);
  uniqueNum=str(nowTime)+str(randomNum);
  print uniqueNum;

The running result obtained is as shown below. It can happen that none of the generated numbers are the same:

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