On 07/23/2017 09:16 AM, Alex Kleider wrote: > On 2017-07-23 01:06, Anish Tambe wrote: >>> for line in file: >> >> This line is not required as the you have opened your file to 'f'. >> 'file' is a built-in class. Type - >> help(file) >> on the interpreter to know more about it. > > This appears to be true in python2x but not in python3: > > alex@X301n3:~$ python3 > Python 3.4.3 (default, Nov 17 2016, 01:11:57) > [GCC 4.8.4] on linux > Type "help", "copyright", "credits" or "license" for more information. >>>> help(file) > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > NameError: name 'file' is not defined >>>> exit() > alex@X301n3:~$ python > Python 2.7.6 (default, Oct 26 2016, 20:32:47) > [GCC 4.8.4] on linux2 > Type "help", "copyright", "credits" or "license" for more information. >>>> help(file) > Help on class file in module __builtin__: > > class file(object) > | file(name[, mode[, buffering]]) -> file object > | > ...
It is nonetheless still true that Python provides context manager support for file objects that behave the same way as described (that is, when handle - called 'f' in the example above - goes out of scope, it is closed for you). Otherwise, the relevant documentation on file objects is now in the IO discussion: https://docs.python.org/3/library/io.html > Also puzzling is that the 'intro' to python2 declares itself to be 'on > linux2' vs just 'on linux' in the case of python3. (Something I'd not > previously noticed.) That's just a cleanup of an old issue, Python3 dropped the "linux2" thing (which was never a great idea, linux kernels are now 4.x after 2.x lived for a very long time, Python never followed those changes nor did it need to); FWIW, the preferred method now to check if a host is linux is to do: if sys.platform.startswith("linux"): instead of checking explicitly for a string "linux", "linux2", etc. _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
