Convert string to decimal (base 10) in Python
Solution 1:
You can simply use int
here:
>>> strs = 'test'
>>> int(strs, 36)
1372205
Or define your own function:
def func(strs):
numerals = "0123456789abcdefghijklmnopqrstuvwxyz"
return sum(numerals.index(x)*36**i for i, x in enumerate(strs[::-1]))
...
>>> func(strs)
1372205
Solution 2:
If your input is in UTF-8 you can encode each byte to Base10, rather than limit yourself to some fixed set of numerals. The challenge then becomes decoding. Some web-based Base10 encoders separate each encoded character/byte with a space. I opted to left-pad with a null character which can be trimmed out.
I am sure there is plenty of room for optimisation here, but these two functions fit my needs:
Encode:
def base10Encode(inputString):
stringAsBytes = bytes(inputString, "utf-8")
stringAsBase10 = ""
for byte in stringAsBytes:
byteStr = str(byte).rjust(3, '\0') # Pad left with null to aide decoding
stringAsBase10 += byteStr
return stringAsBase10
Decode:
def base10Decode(inputString):
base10Blocks = []
for i in range(0, len(inputString), 3):
base10Blocks.append(inputString[i:i+3])
decodedBytes = bytearray(len(base10Blocks))
for i, block in enumerate(base10Blocks):
blockStr = block.replace('\0', '')
decodedBytes[i] = int(blockStr)
return decodedBytes.decode("utf-8")