10 Nov
2017
10 Nov
'17
6:21 p.m.
Nemo:
And for that reason, I have never used Python. (I have a mental block
about that.)
====
I used to feel the same way. A few years ago I held my nose
and jumped in. I'm glad I did; Python is a nifty little
language that, now I know it, hits a sweet spot twixt low-level
C and high-level shell and awk scripts.
Denoting blocks solely by indentation isn't at all bad once
you do it; no worse than adapting from do ... end to C's {}.
What still bugs me about Python:
-- It is unreasonably messy to give someone else a copy of
a program composed of many internal modules. Apparently
you are expected to give her a handful of files, to be
installed in some directory whose name must be added to
the search path in every Python source file that imports
them. I have come up with my own hacky workaround but it
would be nice if the language provided a graceful way to,
e.g., catenate multiple modules into a single source file
for distribution.
-- I miss C's style of for loop, though not often. (Not
quite everything can be turned into a list or an iterator.)
-- I miss one particular case of assigment having a value:
that of
while ((val = function()) != STOP)
do something with val
Again, there are clunky ways to work around this.
As for 80 columns, I'm firmly in the camp that says that
if you need a lot of indentation you're doing it wrong.
Usually it means you should be pulling the details out
into separate functions. Functions that run on for many,
many lines (once upon a time it was meaningful to say
for many pages, but no longer) are just as bad, for the
same reason: it's hard to read and understand the code,
because you have to keep so many details in your head at
once.
Likewise for excessive use of global variables, for that
matter, a flaw that is still quite common in C code.
Having to break an expression or a function call over
multiple lines is more problematic. It's clearer not
to have to do that. It helps not to make function or
variable names longer than necessary, but one can carry
that too far too.
Style and clarity are hard, but they are what distinguishes
a crap hack programmer from a good one.
Norman Wilson
Toronto ON
(Sitting on the lower level of a train in Texas,
not on a pedestal)
10 Nov
10 Nov
6:56 p.m.
New subject: 80 columns ...
On Fri, Nov 10, 2017 at 01:21:09PM -0400, Norman Wilson wrote:
Style and clarity are hard, but they are what
distinguishes
a crap hack programmer from a good one.
Yep. My version of this is "optimize for the readers, there are many
of them and one of you".
11 Nov
11 Nov
6:04 p.m.
New subject: 80 columns ...
On 2017-11-10 13:21, Norman Wilson wrote:
-- It is unreasonably messy to give someone else a
copy of a program
composed of many internal modules. Apparently you are expected to
give her a handful of files, to be installed in some directory whose
name must be added to the search path in every Python source file that
imports them. I have come up with my own hacky workaround but it
would be nice if the language provided a graceful way to, e.g.,
catenate multiple modules into a single source file for distribution.
Aren't to supposed to make an "egg", or something?
Even before those, you could make a package, "sdist" it, and have the
recipients run "python setup.py install". Still simpler process than
installing many C libraries from source ...
-- I miss one particular case of assigment having a
value:
that of
while ((val = function()) != STOP)
do something with val
I was once in a remote job interview with a Ruby shop. I don't know
Ruby, but they said I could use Python. Of course this situation came
up (it's pretty common when you think about it) and on this occasion a
whim made me write it thus:
while True:
val = function()
if val == STOP:
break
do_something()
Their reply was overflowing with shock and horror that I would use
"while True", and that was the end of that opportunity for me.
Apparently Ruby has a construct to handle this cleanly, without having
to call function() from two sites.
Toronto ON
(Sitting on the lower level of a train in Texas, not on a pedestal)
What's a Torontonian doing in Texas? Are you researching the sequel to
"Tideland" ? :-)
--
Please don't Cc: me privately on mailing lists and Usenet,
if you also post the followup to the list or newsgroup.
To reply privately _only_ on Usenet, fetch the TXT record for the domain.
6:30 p.m.
New subject: 80 columns ...
On Sat, Nov 11, 2017, at 12:04, Ian Zimmerman wrote:
On 2017-11-10 13:21, Norman Wilson wrote:
Python has one as well, though it's a bit obscure - ISTR around half of
the people who commented on a thread on the python mailing lists where
this came up weren't familiar with it.
for val in iter(function, STOP):
do_something()
If the function needs arguments, you have to use a lambda. If the
condition is something other than equality to some value... well, you
can hack something together, but it's debatably cleaner than the while
True loop.
(If the function is readline, though, you can just iterate over the file
object)
-- I miss one particular case of assigment having
a value:
that of
while ((val = function()) != STOP)
do something with val
I was once in a remote job interview with a Ruby shop. I don't know
Ruby, but they said I could use Python. Of course this situation came
up (it's pretty common when you think about it) and on this occasion a
whim made me write it thus:
while True:
val = function()
if val == STOP:
break
do_something()
Their reply was overflowing with shock and horror that I would use
"while True", and that was the end of that opportunity for me.
Apparently Ruby has a construct to handle this cleanly, without having
to call function() from two sites.
7:05 p.m.
New subject: 80 columns ...
On 2017-11-11 12:30, Random832 wrote:
for val in iter(function, STOP):
do_something()
A neat trick, thanks.
(If the function is readline, though, you can just
iterate over the
file object)
This doesn't work if the file object can be a tty (such as stdin), IIRC
due to stdio buffering effects.
--
Please don't Cc: me privately on mailing lists and Usenet,
if you also post the followup to the list or newsgroup.
To reply privately _only_ on Usenet, fetch the TXT record for the domain.
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4 comments
4 participants
participants (4)
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Ian Zimmerman -
Larry McVoy -
Norman Wilson -
Random832