Windows Specific Issue and work-around: Chapter 17: flags2_common.py

[Deleted user]

First of all - a well written and complete book for intermediate to advanced Python users. It covers a lot of territory and for the most part will work as is on a variety of systems. I did find one bug in chapter 17 that prevents you from moving through the last part of the chapter. The error is in flags2_common.py on Windows 8-10: Not sure if this effects other systems too. The code provided is this...

def main(download_many, default_concur_req, max_concur_req):

    args, cc_list = process_args(default_concur_req)

    actual_req = min(args.max_req, max_concur_req, len(cc_list))

    initial_report(cc_list, actual_req, args.server)

    base_url = SERVERS[args.server]

    t0 = time.time()

    counter = download_many(cc_list, base_url, args.verbose, actual_req)

    assert sum(counter.values()) == len(cc_list), \

        'some downloads are unaccounted for'

    final_report(cc_list, counter, t0)

For windows, this will throw an error: This code works better...

def main(download_many, default_concur_req, max_concur_req):

    args, cc_list = process_args(default_concur_req)

    actual_req = min(args.max_req, max_concur_req, len(cc_list))

    initial_report(cc_list, actual_req, args.server)

    base_url = SERVERS[args.server]

    t0 = time.time()

    counter = download_many(cc_list, base_url, args.verbose, actual_req)

    assert sum(counter.values()) == len(cc_list), 'some downloads are unaccounted for'
    
    final_report(cc_list, counter, t0)

Let me know if you need clarification.

[stroke-one]

What is the error you get. The only thing different here is that you've removed the line wrap on the assert statement which a) shouldn't be a problem or throw an error and b) puts the line longer than 80 characters which is a violation of PEP 8 as seen here:
https://www.python.org/dev/peps/pep-0008/#maximum-line-length

[Deleted user]

Oddly enough, a syntax error, reproducing it minus personal information which I've substituted - we get this. This is a workaround - not a fix. 80 width on an editor may be an issue, since this is 82 characters.
I'll close if something here is trivial and being overlooked, but it seemed off...

Error:

`Traceback (most recent call last):
File "flags2_threadpool.py", line 49, in
from flags2_common import main, HTTPStatus # <2>
File "C:\countries\flags2_common.py", line 294

^

SyntaxError: invalid syntax`

so... say I'm running flags2_threadpool.py: Then you change flags2_common.py to my version, which is 2 characters in violation of PEP 8, therefor not a fix, but a workaround...

`PS C:\countries> py -3 flags2_threadpool.py
LOCAL site: http://localhost:8001/flags
Searching for 20 flags: from BD to VN
20 concurrent connections will be used.
100%|######################################################################################################################| 20/20 [00:01<00:00, 12.67it/s]

20 flags downloaded.
Elapsed time: 1.62s`

Is this a space case error on my part, or a legit one? I'm having trouble finding a documented version of something similar, so it may be human error of course, somehow, but it seemed like an interpreter problem or something else, so I thought I'd see what the community thought.

Using visual studio 2015 enterprise. The error didn't make sense to me but it's thrown and won't allow flags2_* scripts to run unless you take away the wrap and one line it. I said a work-around because it does violate the principle outlined in PEP 8, but allows you to continue moving if you're encountering an error too - I've since finished the book and didn't have any other problem cases. It didn't make sense to me, but it was the only way the script works as is. Violating a PEP by 2 characters.

Also, I tried toggling word wrap on/off in Visual Studio - didn't make a difference. Went through a couple sanity checks, just didn't get any progress without one-lining.

Any suggestions?