Python stops reading file using read

Question

I\'m trying to read a binary file and am getting confusing results.

f = open(\'foo.dat\',\'r\')

data = f.read()

print len(data), f.tell()

Answer 1

It's probably on Windows and you have a Ctrl-Z (the CP/M end-of-file marker, which was inherited by Windows via MS-DOS). Do this:

f = open('foo.dat','rb') # NOTE b for binary
data = f.read() 
print len(data), f.tell() 
print repr(data[60:70])

and show us the output. Ctrl-Z is '\x1a' aka chr(26).

Answer 2

data is a str object, thus len(data) tells you about the length of this string, not the file length in bytes.