Get random float python

Python Program to Generate Random Float

We can generate a random floating point number in Python using Python random package.

In this tutorial, we shall learn how to generate a random floating point number in the range (0,1) and how to generate a floating point number in between specific minimum and maximum values.

Syntax of random.random()

Following is the syntax of random() function in random module.

random() function returns a random floating point value in between zero and one.

Examples

1. Random Floating Point Number in the Range (0, 1)

In this example, we shall use random.random() function to generate a random floating point number between 0 and 1.

Python Program

import random #generate a random floating point number f = random.random() print(f)

2. Random Floting Point Number in the Range (min, max)

In this example, we shall use random.random() function to generate a random floating point number between a given minimum value and a maximum value.

Python Program

import random #specific range min = 2 max = 10 #generate a random floating point number f = min + (max-min)*random.random() print(f)

min+ ensures that the generated random value has atleast a value of min. (max-min)*random.random() ensures that the value does not exceed the maximum limit.

Explanation

Let us understand the expression used to generate floating point number between a specific range.

f = min + (max-min)*random.random() #random.random generates a value in the range (0, 1) f = min + (max-min)*(0, 1) Resulting Range = (min + (max-min)*0, min + (max-min)*1) = (min + 0, min + max - min) = (min, max)

Summary

In this tutorial of Python Examples, we learned how to generate a random floating point number, with the help of well detailed example programs.

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Модуль Random для генерации случайных чисел в Python

Этот модуль реализует генераторы псевдослучайных чисел под различные потребности.

• Для целых чисел есть выбор одного из диапазона.
• Для последовательностей — выбор случайного элемента, функция случайной сортировки списка и функция случайного выбора нескольких элементов из последовательности.
• Есть функции для вычисления однородных, нормальных (Гауссовских), логнормальных, отрицательных экспоненциальных, гамма и бета распределений.
• Для генерации распределений углов доступно распределение фон Мизеса.

Почти все функции модуля зависят от основной функции random() , которая генерирует случайным образом чисто с плавающей точкой(далее float) равномерно в полуоткрытом диапазоне [0.0, 1.0).

Python использует Mersenne Twister в качестве основного генератора. Он производит 53-битные точные float и имеет период 2**19937-1. Основная его реализация в C быстрая и многопоточная. Mersenne Twister один из наиболее широко протестированных генераторов случайных чисел. Однако, будучи полностью детерминированным, он подходит не для любых целей, особенно для криптографических.

Модуль random так же предоставляет класс SystemRandom . Этот класс использует системную функцию os.urandom() для генерации случайных чисел из источников, которые предоставляет операционная система.

Псевдослучайные генераторы этого модуля не должны использоваться в целях безопасности. Для обеспечения безопасности или для криптографического использования ознакомьтесь с модулем secrets .

Функции для целых чисел

random.randrange(stop)
random.randrange(start, stop[, step])
Возвращает случайно выбранный элемент из range(start, stop, step) . Это эквивалентно choice(range(start, stop, step)) , но не создает объект диапазона.

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Python Random Module

Python has a built-in module that you can use to make random numbers.

The random module has a set of methods:

Method	Description
seed()	Initialize the random number generator
getstate()	Returns the current internal state of the random number generator
setstate()	Restores the internal state of the random number generator
getrandbits()	Returns a number representing the random bits
randrange()	Returns a random number between the given range
randint()	Returns a random number between the given range
choice()	Returns a random element from the given sequence
choices()	Returns a list with a random selection from the given sequence
shuffle()	Takes a sequence and returns the sequence in a random order
sample()	Returns a given sample of a sequence
random()	Returns a random float number between 0 and 1
uniform()	Returns a random float number between two given parameters
triangular()	Returns a random float number between two given parameters, you can also set a mode parameter to specify the midpoint between the two other parameters
betavariate()	Returns a random float number between 0 and 1 based on the Beta distribution (used in statistics)
expovariate()	Returns a random float number based on the Exponential distribution (used in statistics)
gammavariate()	Returns a random float number based on the Gamma distribution (used in statistics)
gauss()	Returns a random float number based on the Gaussian distribution (used in probability theories)
lognormvariate()	Returns a random float number based on a log-normal distribution (used in probability theories)
normalvariate()	Returns a random float number based on the normal distribution (used in probability theories)
vonmisesvariate()	Returns a random float number based on the von Mises distribution (used in directional statistics)
paretovariate()	Returns a random float number based on the Pareto distribution (used in probability theories)
weibullvariate()	Returns a random float number based on the Weibull distribution (used in statistics)

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Working with random in python , generate a number,float in range etc.

In this tutorial, we will learn how to create a _random number _in python. Generating a random number in python is easier than you think. Everything is already defined in a module called random. Just import it and use its inbuilt functions.

I will show you how to print a_ random float_, random float in a range, random integer, random integer in a range, even random number in a range, random element in a sequence and how to shuffle a list.

All the code in this tutorial is compatible with python 3. If you have python 2 installed on your system, maybe you will have to change a few lines.

# Print a random float import random print(random.random()) # Print a random float in range import random print(random.uniform(1,10)) # Print a random integer import random print(random.randrange(10)) # Print an integer number within a range import random print("Random number using randrange : "); print(random.randrange(2,10)) print("Random number using randint : "); print(random.randint(2,10)) # Print only even random number in a range import random print("Even Random number : ") print(random.randrange(2,10,2)) print("Random number Divisible by 5 : ") print(random.randrange(0,100,5)) # Print a random element in a sequence import random days = ["sun","mon","tue","wed","thu","fri","sat"] print(random.choice(days)) # Shuffle a list import random days = ["sun","mon","tue","wed","thu","fri","sat"] for x in range(5): print("shuffling..") random.shuffle(days) print(days)

Example 1: Print a random float :

Don’t forget to import the ’random’ module at the start of the program.

The method_ ‘random()’_ is called to create one random float.

Example 2: Print a random float in a range :

It will print one random number within 1 and 10. uniform() method takes two arguments and returns one random number within the range. This method is useful if you want to get a random number in a range.

Example 3: Print a random integer :

It will print an integer from_ 0 to 9_. Run it and you will always get one value in this range. You can use this method to set the upper range of the generated random number.

Example 4: Print an integer number within a range :

To print an integer in a given range, we have two functions : randrange(a,b) and randint(a,b). The only difference between both is that randint(a,b) will include all integers from a to b, but randrange(a,b) will include integers from a to b-1. That means_ randint(a,b)_ is similar to randrange(a,b+1). Let’s have a look at how to implement both :

Keep running it continuously. At one point, randint will print 10, but randrange will never.

Example 5: Print only even random number in a range :

We can pass one more argument to the randrange function. It is known as step i.e. if we pass 2, it will produce only numbers divisible by 2, for 3 it will produce numbers divisible by 3 etc. Let’s take a look :

The first one will print only even random numbers in between 2 to 9 and the second one will print only random numbers divisible by 5 in between 0 to 99. ’randrange’ is a useful method if we want to produce random integers. Using this method, we can create one random integer less than a number, random integer within a range or a random integer divisible by a specific number.

Example 6: Print a random element in a sequence :

The random module contains one method called choice that takes one sequence as the argument and returns one random element of that sequence. If the sequence is empty, it will raise one IndexError.Let’s take a look at the below program to understand this :

It will print one random word from the provided input sequence.

Module random also has one method called shuffle that shuffles all elements of a list. For example :

It will print output like below :

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