I did read related answers, but still can't figure out how to do my list comprehension properly.
I wrote functions to convert binary to decimal and other way around, but in my decimal to binary conversion I wanted to use list comprehension instead of cycles that I'm using now, yet I can't figure out how to write it correctly.
My code is as follows:
from math import log
def dec_to_binary(n: int) -> str:
"""Convert integer to binary."""
indices = []
while n > 0:
index = int(log(n, 2))
indices.append(index)
n -= 2**index
binary = ['0' for x in range(max(indices)+1)]
for i in indices:
binary[i] = '1'
binary = binary[::-1]
binary = ''.join(binary)
return binary
Here I'm repeatedly calculating a log(2) of a number to get indices which will become 1s in the final binary number. After that I create a list of zeroes with length equal to the highest log value and then replace '0' with '1' in corresponding indices.
This works fine, but I was trying to see if I could do it all in one go, but what I came up with so far doesn't seem to work:
binary = ['0' for x in range(max(indices)+1) if x not in indices else '1']
Interpreter keeps pointing to error at the else statement.
binary = ['0' for x in range(max(indices)+1) if x not in indices else '1']
File "<ipython-input-297-3da1307fffd5>", line 1
binary = ['0' for x in range(max(indices)+1) if x not in indices else '1']
^
SyntaxError: invalid syntax
How can I re-write it correctly?
