Merge pull request #99 from realpython/python-sqlite-sqlalchemy

Python sqlite sqlalchemy

Author: jaschmitt

.gitignore

@@ -108,3 +108,6 @@ ENV/
 
 # Mac
 *.DS_Store
+
+# VS Code workspace
+*.code-workspace

python-sqlite-sqlalchemy/README.md

@@ -1,20 +1,27 @@
-# Python / Sqlite /SqlAlchemy article
+# Python / SQLite /SQLAlchemy article
 
-This repository contains the content and example code 
-for the python/sqlite/sqlaclchemy article I'm writing 
+This repository contains the content and example code
+for the Python / SQLite / SQLAlchemy article I'm writing
 for Real Python.
 
 This project was built using Python 3.8.0
 
+## Python Virtualenv
+
+I use the `pyenv` tool to install Python versions on my Mac. I find it a very useful tool, and the instructions that follow use it, and are based on having Python version 3.8.0 installed using the following command:
+
+```shell
+$ pyenv install 3.8.0
+```
+
 ## Installing The Project
 
-From the main folder take the following steps:
+From the main folder take the following steps (on a Mac):
 
 * Install a Python virtual environment for this project
+  * `pyenv local 3.8.0`
+  * `python -m venv .venv`
 * Activate the virtual environment
+  * `source .venv/bin/activate`
 * Install the project:
-
-```shell script
-python -m pip install -e .
-```
-    
+  * `python -m pip install -e .`

python-sqlite-sqlalchemy/project/build_data/README.md

@@ -1,51 +1,31 @@
 # Build Files Used By The Examples
 
 The code in this directory builds the various data files used
-by the example programs. There are three build programs:
+by the example programs. There is one build program:
+
+* build_author_book_publisher_sqlite.py
 
- * build_temp_data_csv.py
- * build_temp_data_sqlite.py
- * build_author_book_publisher_sqlite.py
- 
-## Build the Temperature CSV File
- 
- The build_temp_data_csv.py file builds a CSV data file
- (temp_data.csv) in the data directory
- containing temperature samples taken by students in a class.
- The top row contains the labels, the students name followed
- by a date value for each Wednesday of the week for a year.
- 
- It then creates data for each sample based on a table of 
- temperature data, +/- 10 to make the data look variable
- and reasonable.
- 
-## Build the Temperature Database File
- 
- The build_temp_data_sqlite.py file builds a Sqlite database
- from the previously created temp_data.csv file called 
- temp_data.db in the data directory. 
- 
 ## Build the Author / Book / Publisher Database File
- 
- The build_author_book_publisher_sqlite.py file builds
- a database from the data/author_book_publisher.csv file.
- This database contains the tables necessary to describe 
- the data and the relationships between the data necessary
- for the examples.
- 
+
+The build_author_book_publisher_sqlite.py file builds
+a database from the `data/author_book_publisher.csv` file.
+This database contains the rows of comma delimited text to describe
+the data and the relationships between the data necessary
+for the examples.
+
 ## Directory Structure
- 
- The directory structure is set up in such a way the
- build programs (as well as the examples) can find the
- data files needed for each one.
- 
+
+The directory structure is set up in such a way the
+build programs (as well as the examples) can find the
+data files needed for each one.
+
 ## Executing the Programs
- 
-  * Activate your Python virtualenv
-  * cd into the build/code directory
-  * python build_temp_data_csv.py - builds the csv data file
-  * python build_temp_data_sqlite.py - builds the temperature data from the csv file
-  * python build_author_book_publisher_sqlite.py - builds the author_book_publisher.db database file
+
+Follow these steps to build the `data/author_book_publisher.db` database file.
+
+* Activate your Python virtualenv
+* cd into the build/code directory
+* python build_author_book_publisher_sqlite.py - builds the author_book_publisher.db database file
 
 
 

python-sqlite-sqlalchemy/project/build_data/build_author_book_publisher_sqlite.py

@@ -5,7 +5,7 @@
 
 import os
 import csv
-from pkg_resources import resource_filename
+from importlib import resources
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
 from project.modules.models import Base
@@ -30,11 +30,13 @@ def populate_database(session, author_book_publisher_data):
 
         author = (
             session.query(Author)
-            .filter(Author.lname == row["lname"])
+            .filter(Author.last_name == row["last_name"])
             .one_or_none()
         )
         if author is None:
-            author = Author(fname=row["fname"], lname=row["lname"])
+            author = Author(
+                first_name=row["first_name"], last_name=row["last_name"]
+            )
             session.add(author)
 
         book = (
@@ -69,19 +71,19 @@ def main():
     print("starting")
 
     # get the author/book/publisher data into a dictionary structure
-    csv_filepath = resource_filename(
+    with resources.path(
         "project.data", "author_book_publisher.csv"
-    )
-    author_book_publisher_data = get_author_book_publisher_data(csv_filepath)
+    ) as csv_filepath:
+        data = get_author_book_publisher_data(csv_filepath)
+        author_book_publisher_data = data
 
     # get the filepath to the database file
-    sqlite_filepath = resource_filename(
+    with resources.path(
         "project.data", "author_book_publisher.db"
-    )
-
-    # does the database exist?
-    if os.path.exists(sqlite_filepath):
-        os.remove(sqlite_filepath)
+    ) as sqlite_filepath:
+        # does the database exist?
+        if os.path.exists(sqlite_filepath):
+            os.remove(sqlite_filepath)
 
     # create the database
     engine = create_engine(f"sqlite:///{sqlite_filepath}")

python-sqlite-sqlalchemy/project/build_data/build_temp_data_csv.py

@@ -1,13 +1,13 @@
-fname,lname,title,publisher
-Issac,Asimov,Foundation,Random House
+first_name,last_name,title,publisher
+Isaac,Asimov,Foundation,Random House
 Pearl,Buck,The Good Earth,Random House
 Pearl,Buck,The Good Earth,Simon & Schuster
 Tom,Clancy,The Hunt For Red October,Berkley
 Tom,Clancy,Patriot Games,Simon & Schuster
 Stephen,King,It,Random House
 Stephen,King,It,Penguin Random House
 Stephen,King,Dead Zone,Random House
-Stephen,King,The Shinning,Penguin Random House
+Stephen,King,The Shining,Penguin Random House
 John,Le Carre,"Tinker, Tailor, Solider, Spy: A George Smiley Novel",Berkley
 Alex,Michaelides,The Silent Patient,Simon & Schuster
 Carol,Shaben,Into The Abyss,Simon & Schuster