Random

🖌 random

NOTES

• For each example, demonstrate how running the code again yields different results

random.choice()

import random

fruits = ['pear','mango','banana','strawberry','kumquat']
selection = random.choice(fruits)
print(selection)

banana

random.randint()

import random

print(random.randint(1, 10))

10

NOTES

• Note that random.randint() can return the boundary numbers
  • so, the return number is anything including and between the arguments.

random.random()

print(random.random())

0.5002419706259531

If you need a random float between 0 and 100, just scale the random number:

print(random.random() * 100)

88.10581258132582

random.sample()

name = 'George Washington'

print(random.sample(name, 2))

['t', 'a']

print(random.sample(name, 5))

['a', 's', 'g', 'g', 't']

print(random.sample(name, len(name)))

['n', 'r', 's', 'G', 'n', 't', 'e', ' ', 'g', 'W', 'i', 'a', 'g', 'e', 'o', 'h', 'o']

🖌 Shuffle

random.sample can be used to get a random sample from a collection.

If you sample all the items in the collection, you essentially get a shuffled version of the data.

import random

def shuffle(string):
    """
    Use random.sample to get the letters in the string in a random order.
    Then join the letters together with the empty string.
    """
    shuffled_letters = random.sample(string, len(string))
    return ''.join(shuffled_letters)

shuffle('12345')

'54123'

shuffle('CS110')

'1CS10'

🖌 Random events at some frequency

apples.py

🧑🏼‍🎨 Umm...

Write a program that takes a frequency (a number between 0 and 1) and a phrase as commandline arguments.

Randomly inject "umm" into a given sentence at the given frequency and print the result.

umm.py

NOTES

• Draw it out!
  • Sentence -> words -> words with umm -> sentence

python umm.py 0.2 'So, I've been meaning to ask, will you go out on a date with me?'

Key Ideas

• random
  • choice
  • randint
  • random
  • sample
• Shuffling strings using random.sample
• Random events at some frequency