Reading the bytes of a PDF

Question

I'm quite a newbie in Python and I want to speed up this method since it takes very long time especially when the size of the input file in Mbs. Also, I couldn't figure out how to use Cython in the for loop. I'm using this function with other functions to compare files byte by byte. Any recommendations?

# this function returns a file bytes in a list
filename1 = 'doc1.pdf'
def byte_target(filename1):
 f = open(filename1, "rb")
 try:
 b = f.read(1)
 tlist = []
 while True:
 # get file bytes
 t = ' '.join(format(ord(x), 'b') for x in b)
 b = f.read(1)
 if not b:
 break
 #add this byte to the list
 tlist.append(t)
 #print b 
 finally:
 f.close()
 return tlist

Answer 1

It's not surprising that this is too slow: you're reading data byte-by-byte. For faster performance you would need to read larger buffers at a time.

If you want to compare files by content, use the filecmp package.

There are also some glaring problems with this code. For example, instead of opening a file, doing something in a try block and closing the file handle manually, you should use the recommended with-resources technique:

 with open(filename1, "rb") as f:
 b = f.read(1)
 # ...

Finally, the function name and all variable names are very poor, and don't help the readers understand their purpose and what you're trying to do.

• amsr: Thank you so much janos, I've changed the code as per your recommendation and it is a bit faster now :)