Tips to code golf in Python [Part-1]

Like in golf, the low score wins, similarly “Code Golf” in Python refers to having the shortest amount of code in terms of “characters” or “bytes”.

Tip #1
Use += instead of append to append something to a list
As an example:

a = [1, 2, 3]
a.append(4)
[1, 2, 3, 4]
# this does the same
a = [1, 2, 3]
a += [4]
[1, 2, 3, 4]

Tip #2
Use List Comprehensions with list indexing to avoid using long if and else statements.

x = 10
if x > 5:
    print("X is greater than 5")
else:
    print("X is lower than 5")
# this does the same
print(["X is lower than 5", "X is greater than 5"][x>5])
"""
x > 5 evaluates to True, which is a subclass of int `1`
On index 1 is "X is greater than 5", thus it gets printed
"""

Tip #3
In case of comparing two values with 1 and 0 can be lowered by 1 char using < or >
The same goes for checking if some value is equal to or greater than or equal to or lower than

x = 0
if x == 0:
# this does the same
if x<1:
a = 10
if a >= 10:
# this does the same by reducing 1 from the limit
if a>9:
if a <= 10:
# this does the same by adding 1 to the limit
if a<11:

Tip #4
Use 1 space indentation instead of 1 tab or 4 spaces indentation

if some > 10:
    print("Hi")
# can be reduced to
if some>10:
 print("Hi") # 1 space indentation
# further one liner
if some>10:print("Hi")

Tip #5
Inbuilt methods like dict.get are extremely useful when a default value is needed

t = {"key1": "value"}
if "key2" in t:
    print(t["key2"])
else:
    print("Not in t")
# can be reduced to
print(t.get("key2","Not in t"))
"""
The syntax for `dict.get()` is
dict.get(key, value_if_key_not_found)
Note: `value_if_key_not_found` defaults to None
"""

Tip #6
Nested for loops using rangecan be converted to a single for loop by using the multiplication * operator

for i in range(a):
    for j in range(b):
        for h in range(c):
            ...
# can be reduced to
for i in range(a*b*c):
    i, j, h = i//c//b, i//c%b, i%c
# two nested for loops
for i in range(a*b):
    i, j = i//b, i%b

Tip #7
Declaring multiple variables in one line

# How kids do it
a = "1"
b = "2"
c = "3"
# How men do it
a,b,c="1","2","3"
# How legends do it
a,b,c="123"
# Take this a meme please

Tip #8
You may have used math.floor and math.ceil several times for easiness and short code but there is a more shorter way to do it

from math import floor, ceil
e = 16/13
print(floor(e))
print(ceil(e))
# can be reduced to
print(e//1)
print(0--e//1))
"""
Note: the shorter code returns a float not an int
"""

Tip #9
Use ; in Python to make your code fit in one line and save indentations spaces/ tabs too

def test():
    x = 10
    y = 20
    print(x, y)
# can be reduced to
def test():x,y=10,20;print(x,y)

Tip #10
Use Python’s inbuilt functions to reduce characters

# `isdigit()`
x = "10"
try:
    x = int(x)
except:
    pass
# can be reduced to
if x.isdigit():x=int(x)
# `islower()` and `isupper()`
x = "hello world 121212121212"
print(x.islower()) # True
x = "HELLO WORLD 121212121212"
print(x.isupper()) # True

That’s it for this part. Hope you learnt something new today that you didn’t know exists in Python. This may help you to boost your code golfing skills. I will be posting many parts on Code Golfing in Python, so stay alert!
My Github: https://github.com/techguy940