listcomprenhension.py

print("List comprenhension")

print("basic form is:  list = [transform sequence [filter] ]")

import randomnum
import string

print("Basic using range")
under_10 = [x for x in range(10)]
print("under 10: " + str(under_10))
print("Basic usage, squares")
squares = [x ** 2 for x in under_10]
print("Squares: " + str(squares))

print("Basic usage, get odd numbers")
odd = [x for x in under_10 if x % 2 > 0]
print("Odds: ", str(odd))

print("Basic usage, get multiples of 10")
mult = [x * 10 for x in under_10]
print("Mult 10: " + str(mult))

print("Basic usage, get all numbers from string")
s = "I work with more than 10 programming languages, but I love C like and currently, I use 3 or 4 languages in my projects (Python, Go, JS, Dart)"
num = [int(ch) for ch in s if ch.isdigit()]
print("List of ints: " + str(num))

print("Basic usage, get index of a list item")
s = ["Rafael", "Guille", "Emi", "Pam", "Rafa"]
print(s)
idx = [k for k, v in enumerate(s) if v == "Rafa"]
print("Index of Rafa: " + str(idx))

print("Basic usage, delete an item from a list")
print(s)
idx = [k for k in s if k != "Rafa"]
print("new list: " + str(idx))

print("Using condition before iterating")
print("Even numbers multiplied by 10 and Odd by 5 in range 10")
l = [x * 10 if x % 2 == 0 else x * 5 for x in range(10)]
print(l)

print("Iterating over 2d array and returns a linear array")
l = [[1, 2], [3, 4], [5, 6]]
print(l)
l = [e for r in l for e in r]
print(l)

print("Replace odd values with -1")
l = [1, 2, 3, 4, 5, 6, 7, 8, 9]
l = [0 if e % 2 == 0 else e for e in l]
print(l)