We can simply use:
crc = struct.unpack('>i', data)
why do people write it like this:
(crc,) = struct.unpack('>i', data)
What does the comma mean?
Advertisement
Answer
The first variant returns a single-element tuple:
In [13]: crc = struct.unpack('>i', '0000') In [14]: crc Out[14]: (808464432,)
To get to the value, you have to write crc[0]
.
The second variant unpacks the tuple, enabling you to write crc
instead of crc[0]
:
In [15]: (crc,) = struct.unpack('>i', '0000') In [16]: crc Out[16]: 808464432