Idiomatic Python

Question 1

x = y = z = 10
x = 11
Whats the value of y, z now?

Answer 1

its still 10

Question 2

How to swap values a and b

Answer 2

(a,b) = (b,a)

Question 3

concatenate_this_list = [“FistString”, “SecondString”, “ThirdString”]
concatenated_string = ‘ ‘.join(concatenate_this_list)
print (concatenated_string)

Answer 3

’ ‘ leaves space between list elements so the result is
FirstString SecondString ThirdString

Question 4

Whats the pythonic way of this:
x=y=z=10
if x<=y and y<=z:
print (“All equal”)

Answer 4

if x<=y<=z

Question 5

Whats the pythonic way of this?
if name == “Tom” or name == “Nick” or name == “Harry”:
is_generic_name = True

Answer 5

is_generic_name = name in [“Tom”, “Nick”, “Harry”]

Question 6

Empty squences like (), [], {} are falsy?

Answer 6

Yes

Question 7

None is falsy?

Answer 7

Yes

Question 8

Numeric 0 and emtpy strings are falsy?

Answer 8

yes

Question 9

Whats the pythonic for this?
colors = [“red”, “green”, “blue”, “yellow”]
for i in range(len(colors)-1, -1, -1):
print (colors[i])

Answer 9

for color in reversed(colors)

Question 10

Output?
fruits = [“strawberry”, “watermelon”, “banana”]
colors = [“red”, “green”, “yellow”, “blue”]
for fruit, color in zip(fruits, colors):
print (f”{fruit} –> {color}”)

Answer 10

strawberry –> red
watermelon –> green
banana –> yellow

Question 11

original_list = range(4, -4, -1)
has_some_positive = any(element >0 for element in original_list)

Answer 11

True

Question 12

fruit_colors = {“watermelon”: “green”, “strawberry”: “red”, “banana”: “yellow”}

for fruit, color in fruit_colors.items():
print (f”Fruit: {fruit} is {color}”)

Answer 12

.keys if u dont care about the values
.items if you care both about the keys and values

Question 13

fruits = [“strawberry”, “watermelon”, “banana”]
colors = [“red”, “green”, “yellow”]

fruit_colors = dict(zip(fruits, colors))

print (fruit_colors)

Answer 13

Creates a dict out of lists

Question 14

person_name = {“first_name”: “Nikos”, “surname”: “Giatrakos”}
person_characteristics = {“age”: 40, “height”: 1.85}

person = {**person_name, **person_characteristics}
person

Answer 14

merge dictionaries

Question 15

Pythonic of :

def check_generic_name(name):
if name in [“Tom”, “Nick”, “Harry”]:
return name
return “Not included”

print (check_generic_name(“Nick”))

Answer 15

def check_generic_name(name):
return name if name in [“Tom”, “Nick”, “Harry”] else “Not included”

print (check_generic_name(“Nikos”))