How to convert a string of a decimal number from any base to a decimal number? [closed]

I'm looking to write a function that can convert a string with a given base to a decimal number.

Let's say the function is convert calling convert should give me the following output

convert

convert

convert('3.14', base=10) ~= 3.14
convert('100.101', base=2) == 4.625


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2 Answers
2

Python supports already. Simply use my_int = int(str, base)

my_int = int(str, base)

To convert floating-point numbers from one base to another, you can just break the number in half, handle the whole and the part separately, and then join them back together.

num = '100.101'
base = 2

# split into whole and part
whole = num[:num.index('.')]
part = num[num.index('.') + 1:]

# get the logarithmic size of the part so we can treat it as a fraction
# e.g. '101/1000'
denom = base ** len(part)

# use python's built-in base conversion to convert the whole numbers
# thanks @EthanBrews for mentioning this
b10_whole = int(whole, base=base)
b10_part = int(part, base=base)

# recombine the integers into a float to return
b10_num = b10_whole + (b10_part / denom)
return b10_num


Thanks to the other answerer @EthanBrews for mentioning that integer stuff was already built-in. Unfortunately the same construction doesn't same to exist for float.

float