More Strings

🎨 .split()

question = 'Do you know the muffin man?'
print(question.split())

statement = "It is possible that I might, under other circumstances, have something to say, but right now I don't"
print(statement.split(','))

NOTES

• you can split on more than just white space
• in this example, ',' is the delimiter

The string you use as the separator is called the delimiter

text = "This  string   has\nvery     unusual    \n     whitespace!"
print(text)

text.split()

text.split(' ')

text.split('\n')

NOTES

• When no argument is provided, split will combine all whitespace into a single delimiter

🎨 .join()

' '.join(['a','bunch','of','words'])

','.join(['45', '670', '324'])

sentences = [
    'This is the first line.', 
    'This is the second line.', 
    'And here is another line for good measure.'
]
print(sentences)

text = '\n'.join(sentences)
print(text)

' and '.join(['apples','oranges','bananas','pears'])

NOTES

• you can join on more than a single character
• notice also that the delimiter goes in between, but not before or after the items in the list

'  '.join('Cougars')

NOTES

• you can join anything that is iterable and returns a sequence of strings

' '.join([1, 2, 3, 4])

NOTES

• you can only join strings
• first convert to strings, then join

🖌 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)

random.randint()

import random

print(random.randint(1, 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())

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

print(random.random() * 100)

random.sample()

name = 'Washington'

print(random.sample(name, 2))

print(random.sample(name, 5))

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

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.

🖌 Events at Random Frequency

%%file apples.py
def apples(size):
    result = []
    while len(result) < size:
        if random.random() < 0.1:
            result.append('bananas!')
        else:
            result.append('apples')
    return result

size = int(sys.argv[1])
fruit = apples(size)
print(' '.join(fruit))

apples.py

🧑🏼‍🎨 Umm...

Randomly inject "umm" into a given sentence at a frequency of about 20%.

umm.py

NOTES

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

import random
import sys


def ummify(words):
    """Randomly inject 'umm' into the given text at a frequence of 20%"""
    words = text.split(' ')
    result = []
    for word in words:
        if random.random() < 0.2:
            result.append('umm')
        result.append(word)
    return ' '.join(result)


text = sys.argv[1]
print(ummify(text))

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

🖌 Early Return

def has_digit(text):
    """Returns true if any character in `text` is a digit"""
    for char in text:
        if char.isdigit():
            return True
    return False

NOTES

• The for loop never gets to finish. That's OK.
• return False is correct because if we didn't return True, we never found a digit.
• This pattern comes up often when you are checking for the existing or absence of some property

has_digit('abcdefg123')

has_digit('a few words')

👩🏻‍🎨 has_byu

def has_byu(lines):
    """Returns True if any of the lines contain the text 'BYU'
    lines = ['abc', 'byu', '123'] => True
    lines = ['123', 'abc'] => False
    """
    for line in lines:
        if 'BYU' in line or 'byu' in line:
            return True
    return False
    

def has_byu(lines):
    """Returns True if any of the lines contain the text 'BYU'"""
    for line in lines:
        if 'BYU' in line:
            return True
    return False

has_byu(['Yesterday I hiked Y mountain','I saw a squirrel','The squirrel ran away'])

has_byu(['I need to buy books','The BYU bookstore has chocolate-covered cinnammon bears','I have a plan!'])

👨🏼‍🎨 all_digits

def all_digits(text):
    """Returns True if all of the characters are digits"""
    for char in text:
        if not char.isdigit():
            return False
    return True

def all_digits(text):
    """Returns True if all of the characters are digits"""
    for c in text:
        if not c.isdigit():
            return False
    return True

all_digits('12345')

all_digits('123e32')

Key Ideas

• .split() and .join()
• random
• Events at random frequency
• Early return