Python Random Numbers: randint, random.choiceUse the random module and the randint method. Call random.choice on a list.
Random. The patterns on a butterfly's wings are detailed. See the colors and shapes. But they are not random. There is a pattern to these patterns.
For Python developers there is a pseudo-random number generator. With this we could generate many patterns for a butterfly's wings. We call randint and random.choice.
With the random module
(and randint) we easily generate random numbers. The randint() method receives 2 arguments. They are both inclusive (including the numbers).While
Argument 1: The first argument to randint is the inclusive lower value of the range. Randint can return this value.
Argument 2: The second argument to randint is the inclusive upper value of the range. Randint can also return this value.
Python program that uses random, randint
i = 0
while i < 10:
# Get random number in range 0 through 9.
n = random.randint(0, 9)
i += 1
In this Python example, we use random.choice() on a list and a tuple. When we execute this program, it gives a different result—unless the random choices are the same.
List, tuple: The random.choice method supports lists and tuples. As we see next, it also chooses a random character from a string.ListTuple
Python program that uses random.choice
# Use random.choice on a list.
arr = [1, 5, 9, 100]
n = random.choice(arr)
# Use random.choice on a tuple.
tup = (2, 4, 6)
y = random.choice(tup)
Random lowercase letter.
This program generates a random lowercase char. It only supports the chars A through Z, but it is easily modified.
Tip: To generate a random char from any set, you can just change the string literal in this program.
Tip 2: A list could also be used: we could add in a loop (or list comprehension) all the desired letters.
Python program that generates random lowercase letter
# This string literal contains all lowercase ASCII letters.
values = "abcdefghijklmnopqrstuvwxyz"
for i in range(0, 10):
# random.choice returns a random character.
letter = random.choice(values)
Random.choice can be used to easily create random text or phrases. Here we populate a list with seven words and then add five random choices to a string.
Strip, capitalize: We call strip to remove trailing punctuation and spaces. Capitalize improves the phrase's appearance.StripLower, Upper
Note: I encourage you to research Markov chains for better random text generation. This program is not good.
Quote: Markov processes can also be used to generate superficially real-looking text given a sample document.Markov chain: Wikipedia
Python program that creates random phrases
# Create a list of words.
words = 
# Create sentence of five words.
result = ""
for i in range(0, 5):
result += random.choice(words) + " "
# Fix trailing punctuation and capitalize.
result = result.strip(" ,")
result = result.capitalize()
result += "!"
Hello, here cat, buy free!
The randint and random.choice methods are excellent choices for pseudo-random numbers. They are clear. They are easy to remember and need few comments.
One key thing to remember: the randint method receives two arguments that are inclusive. So the highest number is included. This differs from other languages like Java.
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