035_mapping.py

# Video alternative: https://vimeo.com/954334322/c5a36d4407#t=0

from lib.helpers import check_that_these_are_equal

# Mapping is going through a list and converting ('mapping')
# each item to another item. This is useful when you want
# to perform the same operation across a list of items.

# For example:

# * Getting the price of each in a list of products
# * Making each in a list of words uppercase
# * Finding the first letter of each in a list of words

# Here's an example:

words = ['I', 'need', 'another', 'five', 'years']

first_letters = [] # This is our accumulator again

for word in words: # We go through each word
  first_letter = word[0] # Get the first letter
  # And append it to our accumulator list:
  first_letters.append(first_letter)

print(words)
print(first_letters)

# @TASK: run this program to see what it does.

# @TASK: Complete this exercise.

print("")
print("Function: add_one_hundred_to_numbers")

# Return a new list of each number with 100 added
def add_one_hundred_to_numbers(numbers):
  pass

check_that_these_are_equal(
  add_one_hundred_to_numbers([1, 2, 3, 4]), [101, 102, 103, 104])
check_that_these_are_equal(
  add_one_hundred_to_numbers([2, 3, 4, 5]), [102, 103, 104, 105])

# When you're done, move on to 036_filtering.py