packtpublishing/expert-python-programming-fourth-edition

Expert Python Programming, Fourth Edition published by Packt

expert-python-programming-fourth-edition's Issues

Error at threaded_visits.py Ch6, Multiprocessing

Hi there,

Concurrency is great topic. I followed the code regarding threaded_visits.py. Authors argued that when I will run the file, I will get unexpected results. However, I am getting expected 10_000_000 value for thread_visits.

My hypothesis: There might be changes in threading standard library.
Looking for your reply!

from threading import Thread

thread_visits = 0

def visit_counter():
    global thread_visits 
    for i in range(100_000):
        # value = thread_visits
        thread_visits +=  1

if __name__ == "__main__":
    thread_count = 100
    threads = [
        Thread(target=visit_counter)
        for _ in range(thread_count)
    ]
    for thread in threads:
        thread.start()
    
    for thread in threads:
        thread.join()
    print(f"{thread_count=}, {thread_visits=}")

(my_bert) (base) sardor@Sardors-MacBook-Pro Concurrency % python3 thread_chaos.py
thread_count=100, thread_visits=10000000
(my_bert) (base) sardor@Sardors-MacBook-Pro Concurrency % python3 thread_chaos.py
thread_count=100, thread_visits=10000000
(my_bert) (base) sardor@Sardors-MacBook-Pro Concurrency % python3 thread_chaos.py
thread_count=100, thread_visits=10000000
(my_bert) (base) sardor@Sardors-MacBook-Pro Concurrency % python3 thread_chaos.py
thread_count=100, thread_visits=10000000

Error when getting code from repository using git clone

I get an error when running git clone to extract the code. The error message:

error: invalid path 'Chapter 5/01 - A bit of history: zope.interface/colliders_interfaces.py'

Please see screenshot attached.

Should itsdangerous and Jinja2 be installed in Dockerfile (Chapter 12, Section 6)?

Problem

In the Chapter 12, Section 6, docker-compose reports error for app_1.

app_1         | Traceback (most recent call last):
app_1         |   File "/app/tracking.py", line 3, in <module>
app_1         |     from flask import Flask, request, Response
app_1         |   File "/usr/local/lib/python3.9/site-packages/flask/__init__.py", line 14, in <module>
app_1         |     from jinja2 import escape
app_1         | ImportError: cannot import name 'escape' from 'jinja2' (/usr/local/lib/python3.9/site-packages/jinja2/__init__.py)

Suggestion

I think that itsdangerous and Jinja2 should be installed explicitly like below (c.f. Flask issue).

RUN pip install \
 Flask==1.1.2 \
 redis==3.5.3 \
 Flask_Injector==0.12.3 \
 prometheus-client==0.10.1 \
 jaeger-client==4.4.0 \
 opentracing==2.4.0 \
 'Werkzeug<2.0.0' \
 Flask-OpenTracing==1.1.0 \
 itsdangerous==2.0.1 \
 Jinja2==3.0.3

(The versions of its dangerous and Jinja2 are just example. No specific reason.)

With this change, the docker-compose error resolved and API request(http://localhost:8000/test) succeeded

Cannot Clone Repository

Cannot Clone Repository from this location.
Also if I fork the repository. I cannot clone it from the fork location.

Please define `PY_SSIZE_T_CLEAN`

https://github.com/PacktPublishing/Expert-Python-Programming-Fourth-Edition./blob/ba386da307804d559a279d4cd0eaa76041e3c318/Chapter%209/02%20-%20Pure%20C%20extensions/fibonacci.c#L1

Please #define PY_SSIZE_T_CLEAN before #include <Python.h>.

See https://docs.python.org/3.10/c-api/arg.html#strings-and-buffers

Note For all # variants of formats (s#, y#, etc.), the macro PY_SSIZE_T_CLEAN must be defined before including Python.h. On Python 3.9 and older, the type of the length argument is Py_ssize_t if the PY_SSIZE_T_CLEAN macro is defined, or int otherwise.

Your sample code doesn't use '#' format so it is not mandatory. But "define PY_SSIZE_T_CLEAN always" is good advice for new extension authors.

how time to publish Fourth-Edition.

15days ago ,so ,its quickly?