Floating point to 16 bit Twos Complement Binary, Python -

so think questions have been asked before i'm having quite bit of trouble getting implemented.

i'm dealing csv files contain floating points between -1 , 1. of these floating points have converted 16 bit 2s complement without leading '0b'. there, convert number string representation of 2s complement, , of csv written written .dat file no space in between. example, if read in csv file , has 2 entries [0.006534, -.1232], convert each entry respective 2s complement , write them 1 after onto .dat file.

the problem i'm getting stuck in code on how convert floating point 16 bit 2s complement. i've been looking @ other posts this , i've been told use .float() function i've had no luck.

can me write script take in floating point number, , return 16 bit 2s complement string of it? has 16 bits because i'm dealing mit 16 standard.

i using python 3.4 btw

to answer question in title: convert python float ieee 754 half-precision binary floating-point format, use binary16:

>>> binary16 import binary16 >>> binary16(0.006534) b'\xb0\x1e' >>> binary16(-.1232) b'\xe2\xaf' 

numpy produces similar results:

>>> import numpy np >>> np.array([0.006534, -.1232], np.float16).tostring() b'\xb1\x1e\xe3\xaf' >>> np.array([0.006534, -.1232], '>f2').tostring() # big-endian b'\x1e\xb1\xaf\xe3' 

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my goal save amplitudes ecg mit signal format 16
..snip..
input .csv file containing f.p. values of amplitude .wav file (which recording of ecg).

you read wav file directly , write corresponding 16-bit two's complement amplitudes in little-endian byte order unused high-order bits sign-extended significant bit ('<h' struct format):

#!/usr/bin/env python3 import wave  wave.open('ecg.wav') wavfile, open('ecg.mit16', 'wb') output_file:     assert wavfile.getnchannels() == 1 # mono     assert wavfile.getsampwidth() == 2 # 16bit     output_file.writelines(iter(lambda: wavfile.readframes(4096), b'')) 

there bug in python 3 .readframes() returns str instead of bytes sometimes. workaround it, use if not data test works on both empty str , bytes:

#!/usr/bin/env python3 import wave  wave.open('ecg.wav') wavfile, open('ecg.mit16', 'wb') output_file:     assert wavfile.getnchannels() == 1 # mono     assert wavfile.getsampwidth() == 2 # 16bit     while true:         data = wavfile.readframes(4096)         if not data:             break         output_file.write(data)