The random module in Python

The random module in Python

( reproduced from http://www.cnblogs.com/yd1227/archive/2011/03/18/1988015.html)

The random module in Python is used to generate a stochastic number. Here are some of the most commonly used functions in the random module.

Random.random

Random.random () is used to generate a random number of 0 to 1 points: 0 <= N < 1.0

Random.uniform

The function prototype for Random.uniform is: Random.uniform (A, b), which is used to generate a random number of points within a specified range of two parameters, one of which is the upper limit and the other is the lower limit. If a > B, the generated random number n:a <= n <= B. If a <b, then B <= N <= A.

2. Print random.uniform (ten )
4. Print random.uniform ( ten)
6. #----Results (different results on the machine)
8. #18.7356606526
10. #12.5798298022

Print Random.uniform (Ten) Print Random.uniform #----results (different results on the machine) #18.7356606526 # 12.5798298022random.randint

The function prototype for Random.randint () is: Random.randint (A, b), which is used to generate integers in a specified range. Where parameter A is the lower limit, parameter B is the upper limit, the generated random number n:a <= n <= B

2. print random.randint ( , 20)    #生成的随机数n :  12 <= n <= 20&NBSP;&NBSP;
4. Print random.randint ( #结果永远是20 )
6. #print Random.randint (#该语句是错误的). The lower limit must be less than the upper limit.   

Print Random.randint (#生成的随机数n): <= n <= print random.randint #print random.randint (20), ) #该语句是错误的. The lower limit must be less than the upper limit. Random.randrange

The function prototype for Random.randrange is: Random.randrange ([start], stop[, step]), which gets a random number from the specified range, in the collection incremented by the specified cardinality. such as: Random.randrange (10, 100, 2), the result is equivalent from [10, 12, 14, 16, ... 96, 98] gets a random number in the sequence. Random.randrange (10, 100, 2) is equivalent to Random.choice (range (10, 100, 2) on the result.

Random.choice

Random.choice gets a random element from the sequence. Its function prototype is: Random.choice (sequence). The parameter sequence represents an ordered type. Here's a note : sequence is not a specific type in Python, but a series of types. list, tuple, string all belong to sequence. For sequence, you can view the Python manual data Model chapter. Here are some examples of using choice:

2. print random.choice (
4. pr Int random.choice ([ " Jgood ", " is ", ,  "handsome" ,  "boy" Span style= "line-height:normal;" >])   
6. Print Random.choice (("Tuple", "List", "Dict")

Print Random.choice ("Learn Python") print Random.choice (["Jgood", "is", "a", "handsome", "boy"]) print Random.choice (" Tuple "," List "," Dict ")) Random.shuffle

The function prototype for random.shuffle is: random.shuffle (x[, Random]), which is used to disrupt elements in a list. Such as:

2. p = [' Python ', ' is ', ' powerful ', ' simple ', ' and so ' on ... '] /c8>
4. Random.shuffle (P)
6. Print P
8. #----Results (results may vary on different machines.) )
10. #[' powerful ', ' simple ', ' was ', ' Python ', ' and so on ... ']

p = [' Python ', ' is ', ' powerful ', ' simple ', ' and so ' on ... '] Random.shuffle (p) Print P #----Results (results may differ on different machines.) #[' powerful ', ' simple ', ' was ', ' Python ', ' and so on ... ']random.sample

The function prototype for random.sample is: random.sample (sequence, k), which randomly fetches fragments of the specified length from the specified sequence. The sample function does not modify the original sequence.

1. List = [1,, 3, 4, , 6, 7, , 9, 10]  
3. Slice = random.sample (list, 5) #从list中随机获取5个元素, returns as a fragment
5. Print Slice
7. Print list #原有序列并没有改变.   

Random integers:
>>> Import Random
>>> Random.randint (0,99)
21st

Randomly select even numbers between 0 and 100:
>>> Import Random
>>> random.randrange (0, 101, 2)
42

Random floating point number:
>>> Import Random
>>> Random.random ()
0.85415370477785668
>>> random.uniform (1, 10)
5.4221167969800881

Random characters:
>>> Import Random
>>> random.choice (' abcdefg&#%^*f ')
' d '

Select a specific number of characters in more than one character:
>>> Import Random
Random.sample (' Abcdefghij ', 3)
[' A ', ' d ', ' B ']

Select a specific number of characters to form a new string in multiple characters:
>>> Import Random
>>> Import String
>>> String.Join (Random.sample ([' A ', ' B ', ' C ', ' d ', ' e ', ' f ', ' g ', ' h ', ' I ', ' J '], 3)). R
Eplace ("", "" ")
' FIH '

Randomly pick a string:
>>> Import Random
>>> random.choice ([' Apple ', ' pear ', ' peach ', ' orange ', ' Lemon '])
' Lemon '

Shuffle:
>>> Import Random
>>> items = [1, 2, 3, 4, 5, 6]
>>> random.shuffle (items)
>>> Items
[3, 2, 5, 6, 4, 1]

Reprinted from Http://www.cnblogs.com/yd1227/archive/2011/03/18/1988015.html

The random module in Python