Pythonic Code

Question 1

Which is considered more “Pythonic”

i = 0
while i < len(my_list):
print(my_list[i])
i += 1

or

for item in my_list:
print(item)

Answer 1

for item in my_list:
print(item)

Question 2

Which is considered more “Pythonic”

a, b = b, a

or

temp = a
a = b
b = temp

Answer 2

a, b = b, a

Question 3

Which is considered more “Pythonic”

evens = []
for x in numbers:
if x % 2 == 0:
evens.append(x)

or

evens = [x for x in numbers if x % 2 == 0]

Answer 3

evens = [x for x in numbers if x % 2 == 0]

Question 4

Which is considered more “Pythonic”

for i, item in enumerate(items):
print(i, item)

or

i = 0
for item in items:
print(i, item)
i += 1

Answer 4

for i, item in enumerate(items):
print(i, item)

Question 5

Which is considered more “Pythonic”

for i in range(len(names)):
print(names[i], scores[i])

or

for name, score in zip(names, scores):
print(name, score)

Answer 5

for name, score in zip(names, scores):
print(name, score)

Question 6

Which is considered more “Pythonic”

found = “apple” in items

or

found = False
for item in items:
if item == “apple”:
found = True
break

Answer 6

found = “apple” in items

Question 7

Which is considered more “Pythonic”

found = False
for word in words:
if word in text:
found = True
break

or

found = any(word in text for word in words)

Answer 7

found = any(word in text for word in words)

Question 8

Which is considered more “Pythonic”

x, y = coords

or

x = coords[0]
y = coords[1]

Answer 8

x, y = coords

Question 9

Which is considered more “Pythonic”

f = open(“file.txt”)
data = f.read()
f.close()

or

with open(“file.txt”) as f:
data = f.read()

Answer 9

with open(“file.txt”) as f:
data = f.read()

Question 10

Which is considered more “Pythonic”

commands = {
“start”: start,
“stop”: stop,
“pause”: pause
}
commands[command] ()

or

xxxif command == “start”:
start()
elif command == “stop”:
stop()
elif command == “pause”:
pause()

Answer 10

commands = {
“start”: start,
“stop”: stop,
“pause”: pause
}
commands[command] ()

Question 11

Which is considered more “Pythonic”

if “user” in data:
username = data[“user”]
else:
username = “Guest”

or

username = data.get(“user”, “Guest”)

Answer 11

username = data.get(“user”, “Guest”)

Question 12

Which is considered more “Pythonic”

if name in {“Alice”, “Bob”, “Charlie”}:
…

or

if name in [“Alice”, “Bob”, “Charlie”]:
…

Answer 12

if name in {“Alice”, “Bob”, “Charlie”}:
…

Question 13

Which is considered more “Pythonic”

users.sort(key=lambda x: x.age)

or

sorted_users = sorted(users, key=lambda x: x.age)

Answer 13

sorted_users = sorted(users, key=lambda x: x.age)

Question 14

Which is considered more “Pythonic”

counts = {}
for letter in text:
if letter in counts:
counts[letter] += 1
else:
counts[letter] = 1

or

from collections import Counter
counts = Counter(text)

Answer 14

from collections import Counter
counts = Counter(text)

Question 15

Which is considered more “Pythonic”

for _ in range(5):
do_something()

or

for i in range(5):
do_something()

Answer 15

for _ in range(5):
do_something()

Question 16

Which is considered more “Pythonic”

for x in items:
if x == target:
break
else:
print(“Target not found!”)

or

found = False
for x in items:
if x == target:
found = True
break

if not found:
print(“Target not found!”)

Answer 16

for x in items:
if x == target:
break
else:
print(“Target not found!”)

Question 17

Which is considered more “Pythonic”

lst = [1, 2, 3, 4, 5]
first = lst[0]
middle = lst[1:-1]
last = lst[-1]

or

first, *middle, last = [1, 2, 3, 4, 5]

Answer 17

first, *middle, last = [1, 2, 3, 4, 5]

Question 18

def make_negative(number):

Write the body of this function to return a negative number - even if given a negative number!

Answer 18

return -abs(number)

abs() removes the sign of the number - always making it positive (or zero)

This is the most Pythonic way