python syntax cheat sheet advanced pdf code example

Example 1: python codes and answers cheat code pdf

from array import array 
 
numbers = array("i", [1, 2, 3])

Example 2: python codes and answers cheat code pdf

# Creating lists
letters = ["a", "b", "c"]     
matrix = [[0, 1], [1, 2]]
zeros = [0] * 5
combined = zeros + letters
numbers = list(range(20))
 
# Accessing items
letters = ["a", "b", "c", "d"]
letters[0]  # "a"
letters[-1] # "d"
 
# Slicing lists 
letters[0:3]   # "a", "b", "c"
letters[:3]    # "a", "b", "c"
letters[0:]    # "a", "b", "c", "d"
letters[:]     # "a", "b", "c", "d"
letters[::2]   # "a", "c"
letters[::-1]  # "d", "c", "b", "a" 
 
# Unpacking 
first, second, *other = letters 
 
# Looping over lists 
for letter in letters: 
    ... 
 
for index, letter in enumerate(letters): 
    ... 
 
# Adding items 
letters.append("e")
letters.insert(0, "-")
 
# Removing items 
letters.pop()
letters.pop(0)
letters.remove("b")
del letters[0:3]
 
# Finding items 
if "f" in letters: 
    letters.index("f")
 
# Sorting lists 
letters.sort()
letters.sort(reverse=True) 
 
# Custom sorting 
items = [
    ("Product1", 10),
    ("Product2", 9),
    ("Product3", 11)
]
 
items.sort(key=lambda item: item[1])
 
# Map and filter 
prices = list(map(lambda item: item[1], items))
expensive_items = list(filter(lambda item: item[1] >= 10, items))
 
# List comprehensions 
prices = [item[1] for item in items]
expensive_items = [item for item in items if item[1] >= 10]
 
# Zip function 
list1 = [1, 2, 3]
list2 = [10, 20, 30]
combined = list(zip(list1, list2))    # [(1, 10), (2, 20)]