floatsBase64.py

#! /usr/bin/env python

import random
import struct
import base64

# Create list of random floating point values
listFloatIn = []

for i in range(20):
    numberIn = random.uniform(0, 1)
    listFloatIn.append(numberIn)

# Pack all floats in list into one bytes object
# (8 bytes for each number, big-Endian byte order)
bufIn = struct.pack('!%sd' % len(listFloatIn), *listFloatIn)

# Encode bytes object to URL-safe base64 (returns bytes object)
bufInBase64 = base64.urlsafe_b64encode(bufIn)

# Decode base64 encoded data back to original bytes object
bufOut = base64.urlsafe_b64decode(bufInBase64)

# Create output list
listFloatOut = []

# Iterate over decoded bytes object, and unpack 8 bytes at a time 

offset = 0

for i in range(int((len(bufOut))/8)):
    # Unpack 8 bytes at a time
    numberOut = struct.unpack('!d', bufOut[offset:offset+8])[0]
    listFloatOut.append(numberOut)
    offset +=8

# Print base64 encoded data to screen (decoding to ascii first)
print("---\nBase 64 encoded string:")
print(bufInBase64.decode('ascii'))
print("---\n")

# Print table with values from listFloatIn versus corresponding
# values in listFloatOut
print("{:<20} {:<20}".format("numberIn", "numberOut"))
print("-----------------------------------")
for i in range(len(listFloatIn)):
    print("{:<20} {:<20}".format(listFloatIn[i], listFloatOut[i]))