How can I "read" specific parts of numbers (int) in Python?

Question

I want to read the parts of numbers.
So if you have 123, I want to use the 1 the 2 and the 3 separately.

As if you would use
a = 123
print([0]
#output: 1

Can I do this in a different way than converting them to strings?

Answer 1

Using a list comprehension like this:

num = 123
lst_int = [int(x) for x in str(num)]
print(lst_int)
# output: [1, 2, 3]
# then you can iterate on this list or pick position with index or slice:
# pick first and last digit:
print(lst_int[0]) # -> 1
print(lst_int[-1]) # -> 3

Answer 2

no str

l = []
n = 123
while n:
l.insert(0,n%10)
n//=10
print(l)

more pythonic version though is better

print([*map(int,str(123))])

Answer 3

You can do

a = 123

b, c, d = a//100, (a%100)//10, a%10

print(b, c, d) #1 2 3

but I don't think there's a way of just picking the first digit without turning it into a string or doing some mathematical manipulation.

Answer 4

thanks All for your replies.
Choe could you explain your pythonic version? I’d like to understand what happens