Merge branch 'master' into numpy-tutorial

Author: jaschmitt

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,42 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+:information_source: Please note that the best way to get support for Real Python courses & articles is to join one of our [weekly Office Hours calls](https://realpython.com/office-hours/) or in the [RP Community Slack](https://realpython.com/community/). 
+
+You can report issues and problems here, but we typically won't be able to provide 1:1 support outside the channels listed above.
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+Steps to reproduce the behavior:
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Desktop (please complete the following information):**
+ - OS: [e.g. iOS]
+ - Browser [e.g. chrome, safari]
+ - Version [e.g. 22]
+
+**Smartphone (please complete the following information):**
+ - Device: [e.g. iPhone6]
+ - OS: [e.g. iOS8.1]
+ - Browser [e.g. stock browser, safari]
+ - Version [e.g. 22]
+
+**Additional context**
+Add any other context about the problem here.

README.md

@@ -1,10 +1,18 @@
 # Real Python Materials
 
-Bonus materials, exercises, and example projects for our [Python tutorials](https://realpython.com).
+Bonus materials, exercises, and example projects for Real Python's [Python tutorials](https://realpython.com).
 
 Build Status: [![CircleCI](https://circleci.com/gh/realpython/materials.svg?style=svg)](https://circleci.com/gh/realpython/materials)
 
-## Running Code Style Checks
+## Got a Question?
+
+The best way to get support for Real Python courses & articles and code in this repository is to join one of our [weekly Office Hours calls](https://realpython.com/office-hours/) or to ask your question in the [RP Community Slack](https://realpython.com/community/). 
+
+Due to time constraints we cannot provide 1:1 support via GitHub. See you on Slack or on the next Office Hours call 🙂
+
+## Adding Source Code & Sample Projects to This Repo (RP Contributors)
+
+### Running Code Style Checks
 
 We use [flake8](http://flake8.pycqa.org/en/latest/) and [black](https://github.com/ambv/black) to ensure a consistent code style for all of our sample code in this repository.
 
@@ -15,7 +23,7 @@ $ flake8
 $ black --check .
 ```
 
-## Running Python Code Formatter
+### Running Python Code Formatter
 
 We're using a tool called [black](https://github.com/ambv/black) on this repo to ensure consistent formatting. On CI it runs in "check" mode to ensure any new files added to the repo are following PEP 8. If you see linter warnings that say something like "would reformat some_file.py" it means black disagrees with your formatting. 
 

nlp-sentiment-analysis/sentiment_analyzer.py

@@ -79,19 +79,19 @@ def evaluate_model(tokenizer, textcat, test_data: list) -> dict:
     true_negatives = 0
     false_negatives = 1e-8
     for i, review in enumerate(textcat.pipe(reviews)):
-        true_label = labels[i]
+        true_label = labels[i]["cats"]
         for predicted_label, score in review.cats.items():
             # Every cats dictionary includes both labels, you can get all
             # the info you need with just the pos label
             if predicted_label == "neg":
                 continue
-            if score >= 0.5 and true_label == "pos":
+            if score >= 0.5 and true_label["pos"]:
                 true_positives += 1
-            elif score >= 0.5 and true_label == "neg":
+            elif score >= 0.5 and true_label["neg"]:
                 false_positives += 1
-            elif score < 0.5 and true_label == "neg":
+            elif score < 0.5 and true_label["neg"]:
                 true_negatives += 1
-            elif score < 0.5 and true_label == "pos":
+            elif score < 0.5 and true_label["pos"]:
                 false_negatives += 1
     precision = true_positives / (true_positives + false_positives)
     recall = true_positives / (true_positives + false_negatives)

python-bindings/overview_article/README.md

@@ -0,0 +1,12 @@
+# Real Python - Python Bindings Sample Code Repo
+
+This is the repo to accompany the [Python Bindings](https://realpython.com/python-bindings-overview/) article.
+
+To be able to run the code, you must first install the requirements:
+
+```console
+$ python -m pip install -r requirements.txt
+```
+This should be done inside a virtual environment.
+
+Once that is installed, you can use the invoke tool mentioned in the article to build and run the tests. See the tasks.py file or run invoke --list to get more details.

python-bindings/overview_article/cffi_test.py

@@ -1,4 +1,5 @@
 #!/usr/bin/env python3
+# IDE might complain with "no module found" here, even when it exists
 import cffi_example
 
 if __name__ == "__main__":

python-bindings/overview_article/cmult.h

@@ -1 +1,7 @@
-float cmult(int int_param, float float_param);
+#ifdef _MSC_VER
+    #define EXPORT_SYMBOL __declspec(dllexport)
+#else
+    #define EXPORT_SYMBOL
+#endif
+
+EXPORT_SYMBOL float cmult(int int_param, float float_param);

python-bindings/overview_article/ctypes_test.py

@@ -1,13 +1,14 @@
 #!/usr/bin/env python
 """ Simple examples of calling C functions through ctypes module. """
 import ctypes
-import pathlib
-
+import sys
 
 if __name__ == "__main__":
     # Load the shared library into c types.
-    libname = pathlib.Path().absolute() / "libcmult.so"
-    c_lib = ctypes.CDLL(libname)
+    if sys.platform.startswith("win"):
+        c_lib = ctypes.CDLL("cmult.dll")
+    else:
+        c_lib = ctypes.CDLL("libcmult.so")
 
     # Sample data for our call:
     x, y = 6, 2.3

python-bindings/overview_article/tasks.py

@@ -1,48 +1,93 @@
 """ Task definitions for invoke command line utility for python bindings
-    overview article. """
+    overview article.
+"""
 import cffi
 import invoke
 import pathlib
+import sys
+import os
+import shutil
+import re
+import glob
+
+on_win = sys.platform.startswith("win")
 
 
 @invoke.task
 def clean(c):
     """ Remove any built objects """
-    for pattern in ["*.o", "*.so", "cffi_example* cython_wrapper.cpp"]:
-        c.run("rm -rf {}".format(pattern))
+    for file_pattern in (
+        "*.o",
+        "*.so",
+        "*.obj",
+        "*.dll",
+        "*.exp",
+        "*.lib",
+        "*.pyd",
+        "cffi_example*",  # Is this a dir?
+        "cython_wrapper.cpp",
+    ):
+        for file in glob.glob(file_pattern):
+            os.remove(file)
+    for dir_pattern in "Release":
+        for dir in glob.glob(dir_pattern):
+            shutil.rmtree(dir)
 
 
 def print_banner(msg):
     print("==================================================")
     print("= {} ".format(msg))
 
 
-@invoke.task
-def build_cmult(c):
+@invoke.task()
+def build_cmult(c, path=None):
     """ Build the shared library for the sample C code """
-    print_banner("Building C Library")
-    invoke.run("gcc -c -Wall -Werror -fpic cmult.c -I /usr/include/python3.7")
-    invoke.run("gcc -shared -o libcmult.so cmult.o")
-    print("* Complete")
+    # Moving this type hint into signature causes an error (???)
+    c: invoke.Context
+    if on_win:
+        if not path:
+            print("Path is missing")
+        else:
+            # Using c.cd didn't work with paths that have spaces :/
+            path = f'"{path}vcvars32.bat" x86'  # Enter the VS venv
+            path += f'&& cd "{os.getcwd()}"'  # Change to current dir
+            path += "&& cl /LD cmult.c"  # Compile
+            # Uncomment line below, to suppress stdout
+            # path = path.replace("&&", " >nul &&") + " >nul"
+            c.run(path)
+    else:
+        print_banner("Building C Library")
+        cmd = "gcc -c -Wall -Werror -fpic cmult.c -I /usr/include/python3.7"
+        invoke.run(cmd)
+        invoke.run("gcc -shared -o libcmult.so cmult.o")
+        print("* Complete")
 
 
-@invoke.task(build_cmult)
+@invoke.task()
 def test_ctypes(c):
     """ Run the script to test ctypes """
     print_banner("Testing ctypes Module")
-    invoke.run("python3 ctypes_test.py", pty=True)
+    # pty and python3 didn't work for me (win).
+    if on_win:
+        invoke.run("python ctypes_test.py")
+    else:
+        invoke.run("python3 ctypes_test.py", pty=True)
 
 
-@invoke.task(build_cmult)
+@invoke.task()
 def build_cffi(c):
     """ Build the CFFI Python bindings """
     print_banner("Building CFFI Module")
     ffi = cffi.FFI()
 
-    this_dir = pathlib.Path().absolute()
+    this_dir = pathlib.Path().resolve()
     h_file_name = this_dir / "cmult.h"
     with open(h_file_name) as h_file:
-        ffi.cdef(h_file.read())
+        # cffi does not like our preprocessor directives, so we remove them
+        lns = h_file.read().splitlines()
+        flt = filter(lambda ln: not re.match(r" *#", ln), lns)
+        flt = map(lambda ln: ln.replace("EXPORT_SYMBOL ", ""), flt)
+        ffi.cdef(str("\n").join(flt))
 
     ffi.set_source(
         "cffi_example",
@@ -66,7 +111,7 @@ def build_cffi(c):
 def test_cffi(c):
     """ Run the script to test CFFI """
     print_banner("Testing CFFI Module")
-    invoke.run("python3 cffi_test.py", pty=True)
+    invoke.run("python cffi_test.py", pty=not on_win)
 
 
 @invoke.task()

python-bitwise-operators/README.md

@@ -0,0 +1,22 @@
+# Bitwise Operators in Python
+
+Source code of the least-significant bit **steganography** example from the [Bitwise Operators in Python](https://realpython.com/python-bitwise-operators/) article.  
+
+## Installation
+
+There are no external dependencies except for a Python interpreter.
+
+## Running
+
+Change directory to the current folder, where this `README.md` file is located, and then execute Python module:
+
+```shell
+$ python -m stegano /path/to/bitmap (--encode /path/to/file | --decode | --erase)
+```
+
+For example, to extract a secret file from the attached bitmap, type the following:
+
+```shell
+$ python -m stegano example.bmp -d
+Extracted a secret file: podcast.mp4
+```