def convert_to_bin(): #в бин через hex
    bin_list=[]
    hex_list=[]
    for txt_str in txt_file:
            toHex = lambda string:"".join([hex(ord(char))[2:].zfill(2) for char in string])
            hex_list.append(toHex(txt_str))
    for item in hex_list:
            bin_list.append(bin(int(item,16))[2:])
    return bin_list

#и обратно
i = bin(int(str(data),16))[2:]
i_h = hex(int(i,2))[2:][:-1]
for char in range(0,len(i_h),2):
     char_list.append(chr(int(i_h[char:char+2],16)))

>>> ''.join(map(lambda x:bin(ord(x))[2:],'Привет мир!'))
'110100001001111111010001100000001101000010111000110100001011001011010000101101011101000110000010100000110100001011110011010000101110001101000110000000100001'

>>> 'Привет мир!'.encode('base64')
'0J/RgNC40LLQtdGCINC80LjRgCE=\n'

>>> s = ''.join(map(lambda x:"{0:0>{1}}".format(bin(ord(x))[2:], 16), u'Привет мир'))
>>> s
'0000010000011111000001000100000000000100001110000000010000110010000001000011010100000100010000100000000000100000000001000011110000000100001110000000010001000000'
>>> print u''.join([unichr(int(s[16*i:(i+1)*16],2)) for i in xrange(len(s)/16)])
Привет мир

UnicodeEncodeError: 'ascii' codec can't encode characters in position 0-3: ordinal not in range(128)

char_list.append(''.join([chr(int(datamas[16*i:(i+1)*16],2)&0xFF) for i in xrange(len(datamas)/16)]))