Acquisition of Python,random random numbers

Random number generation

First we need to introduce random in the program "import random as R"

R.random () is used to generate a random floating-point number,

Print (R.random ())           

R.uniform (10,20), generates a random floating-point number, if A>b A is the upper bound and B is the lower limit. If a<b, then B is the upper limit

Print (R.uniform (10,20))            Print (R.uniform (20,10))           
#如果没有给定a, b that would be an error.

>>> print (R.uniform ())

Traceback (most recent):
File "<pyshell#5>", line 1, in <module>
Print (R.uniform ())
Typeerror:uniform () Missing 2 required positional arguments: ' A ' and ' B '
>>> print (R.randint ())

R.randint (A, A, b), generates a random integer, A is the lower bound, and a is the upper limit. Lower limit must be less than upper limit

 >>> print   (R.randint ()) Traceback (most recent): File   <pyshell# 6>  , Line 1, in  <module> Span style= "COLOR: #0000ff" >print   (R.randint ()) Typeerror:randint () missing  2 Required positional arguments:  " a   " and   " b   " >>> print  (R.randint (1,10 1 

>>> Print (R.randint (10,1))
Traceback (most recent):
File "<pyshell#8>", line 1, in <module>
Print (R.randint (10,1))
File "D:\python\lib\random.py", line 222, in Randint
Return Self.randrange (A, b+1)
File "D:\python\lib\random.py", line $, in Randrange
Raise ValueError ("Empty range for Randrange () (%d,%d,%d)"% (Istart, istop, width))
Valueerror:empty range for Randrange () (10,2,-8)
>>>

R.randrange (A,B,1OR2), randomly extracting odd even numbers within a specified range, 1 odd 2 even

>>> R.randrange (0,10,2)           6>>> r.randrange (0,10,1)           1>>> R.randrange (0,10,1)           

R.choice (' QWERTUIOPOLKJHGFFDSA ') and remove a character

Print (R.choice ('qwertyuiop[]lkjhgfdsazxcvbnm'))           kprint(R.choice ( ' qwertyuiop[]lkjhgfdsazxcvbnm ' )            nprint(R.choice ('qwertyuiop[]lkjhgfdsazxcvbnm' ) ))           T

R.sample (str,num), num characters are randomly output and num must be less than or equal to Len (str)

#is less than the character length>>> R.sample ('QWEASD', 2)           ['D','Q']#is greater than the character length>>> R.sample ('QWEASD', 8) Traceback (most recent): File"<pyshell#25>", Line 1,inch<module>R.sample ('QWEASD', 8) File"D:\python\lib\random.py", line 319,inchSampleRaiseValueError ("Sample larger than population or is negative") valueerror:sample larger than populationor  isNegative#is equal to the character length>>> R.sample ('QWEASD', 6)           ['s','D','a','e','W','Q']>>>

Shuffle, that is, random sort

>>> items = [1,2,3,4,5,6]           >>> r.shuffle (items)           >>> Items           [3, 6, 1, 5, 2, 4]

Acquisition of Python,random random numbers