Adding the example program files that go along with the python-sqlite-sqlalchemy article

Author: writeson

python-sqlite-sqlalchemy/README.md

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+# Pythoh / Sqlite /SqlAlchemy article
+
+This repository contains the content and example code 
+for the python/sqlite/sqlaclchemy article I'm writing 
+for Real Python.

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

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+# 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:
+
+ * 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.
+ 
+ ## 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.
+ 
+ # 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
+  
+  
+  
+ 
+ 

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

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+"""
+This program builds the author_book_publisher Sqlite database from the
+author_book_publisher.csv file.
+"""
+
+import os
+import csv
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+from lib.models import Base
+from lib.models import Author
+from lib.models import Book
+from lib.models import Publisher
+
+
+def get_author_book_publisher_data(filepath):
+    """
+    This function gets the data from the csv file
+    """
+    with open(filepath) as csvfile:
+        csv_reader = csv.DictReader(csvfile)
+        data = [row for row in csv_reader]
+        return data
+
+
+def populate_database(session, author_book_publisher_data):
+    # insert the data
+    for row in author_book_publisher_data:
+
+        author = (
+            session.query(Author).filter(
+                Author.lname == row["lname"]).one_or_none()
+        )
+        if author is None:
+            author = Author(fname=row["fname"], lname=row["lname"])
+            session.add(author)
+
+        book = session.query(Book).filter(
+            Book.title == row["title"]).one_or_none()
+        if book is None:
+            book = Book(title=row["title"])
+            session.add(book)
+
+        publisher = (
+            session.query(
+                Publisher
+            ).filter(
+                Publisher.name == row["publisher"]
+            ).one_or_none()
+        )
+        if publisher is None:
+            publisher = Publisher(name=row["publisher"])
+            session.add(publisher)
+
+        # add the items to the relationships
+        author.books.append(book)
+        author.publishers.append(publisher)
+        publisher.authors.append(author)
+        publisher.books.append(book)
+        session.commit()
+
+    session.close()
+
+
+def main():
+    print("starting")
+
+    # get the author/book/publisher data into a dictionary structure
+    path = os.path.dirname(os.path.abspath(__file__))
+    csv_filepath = os.path.join(path, "../data/author_book_publisher.csv")
+    author_book_publisher_data = get_author_book_publisher_data(csv_filepath)
+
+    # get the filepath to the database file
+    sqlite_filepath = os.path.join(path, "../data/author_book_publisher.db")
+
+    # does the database exist?
+    if os.path.exists(sqlite_filepath):
+        os.remove(sqlite_filepath)
+
+    # create the database
+    engine = create_engine(f"sqlite:///{sqlite_filepath}")
+    Base.metadata.create_all(engine)
+    Session = sessionmaker()
+    Session.configure(bind=engine)
+    session = Session()
+    populate_database(session, author_book_publisher_data)
+
+    print("finished")
+
+
+if __name__ == "__main__":
+    main()

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

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+import os
+import csv
+import datetime
+from random import randint
+
+
+start_date = datetime.datetime.strptime("2019-01-02", "%Y-%m-%d")
+
+students = [
+    "John",
+    "Mary",
+    "Susan",
+    "Doug",
+    "Andrew",
+    "George",
+    "Martha",
+    "Paul",
+    "Helen"
+]
+
+temperature_data = [
+    10, 12, 16, 23, 13,
+    12, 14, 22, 25,
+    28, 32, 33, 37,
+    36, 35, 40, 44,
+    45, 50, 52, 58, 60,
+    66, 70, 70, 72,
+    78, 80, 81, 82, 85,
+    88, 90, 87, 90,
+    85, 82, 81, 78,
+    75, 72, 72, 70, 63,
+    65, 62, 60, 45,
+    40, 37, 30, 28
+]
+
+
+def offset_temp(temperature):
+    """
+    This function modifies the temperature +/- a random
+    amount up to 10
+    :param temperature:     temperature to modify
+    :return:                modified temperature
+    """
+    return temperature + randint(-10, 10)
+
+
+def main():
+    # create the CSV file
+    path = os.path.dirname(os.path.abspath(__file__))
+    csv_filepath = os.path.join(path, "../data/temp_data.csv")
+    with open(csv_filepath, "w") as data_fh:
+
+        # create the writer
+        csv_writer = csv.writer(data_fh)
+
+        # write the header
+        header = ["name"]
+        for week in range(0, 52):
+            current_date = start_date + datetime.timedelta(days=week * 7)
+            header.append(current_date.strftime("%Y-%m-%d"))
+        csv_writer.writerow(header)
+
+        # iterate through the students and write their data
+        for student in students:
+            data = [student]
+            # iterate through the weeks
+            for week in range(0, 52):
+                data.append(offset_temp(temperature_data[week]))
+
+            csv_writer.writerow(data)
+
+
+if __name__ == "__main__":
+    main()

python-sqlite-sqlalchemy/build_data/code/build_temp_data_sqlite.py

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+"""
+This program gathers information from the temp_data.db file about temperature
+"""
+
+import os
+import csv
+from datetime import datetime
+from sqlalchemy import create_engine
+from sqlalchemy import Column, Integer, String, Date, Float
+from sqlalchemy.orm import sessionmaker
+from sqlalchemy.ext.declarative import declarative_base
+
+
+Base = declarative_base()
+
+
+class TemperatureData(Base):
+    __tablename__ = "temperature_data"
+    temperature_data_id = Column(Integer, primary_key=True)
+    name = Column(String, nullable=False)
+    date = Column(Date, nullable=False)
+    value = Column(Float, nullable=False)
+
+
+def get_temperature_data(filepath):
+    """
+    This function gets the temperature data from the csv file
+    """
+    with open(filepath) as csvfile:
+        csv_reader = csv.DictReader(csvfile)
+        data = {
+            row["name"]: row
+            for row in csv_reader
+        }
+        for value in data.values():
+            value.pop("name")
+        return data
+
+
+def populate_database(session, temperature_data):
+    # insert the data
+    for student, data in temperature_data.items():
+        for date, value in data.items():
+            temp_data = TemperatureData(
+                name=student,
+                date=datetime.strptime(date, "%Y-%m-%d").date(),
+                value=value
+            )
+            session.add(temp_data)
+        session.commit()
+    session.close()
+
+
+def main():
+    print("starting")
+
+    # get the temperature data into a dictionary structure
+    path = os.path.dirname(os.path.abspath(__file__))
+    csv_filepath = os.path.join(path, "../data/temp_data.csv")
+    temperature_data = get_temperature_data(csv_filepath)
+
+    # get the filepath to the database file
+    sqlite_filepath = os.path.join(path, "../data/temp_data.db")
+
+    # does the database exist?
+    if os.path.exists(sqlite_filepath):
+        os.remove(sqlite_filepath)
+
+    # create and populate the sqlite database
+    engine = create_engine(f"sqlite:///{sqlite_filepath}")
+    Base.metadata.create_all(engine)
+    Session = sessionmaker()
+    Session.configure(bind=engine)
+    session = Session()
+    populate_database(session, temperature_data)
+
+    print("finished")
+
+
+if __name__ == "__main__":
+    main()

python-sqlite-sqlalchemy/build_data/data/author_book_publisher.csv

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+fname,lname,title,publisher
+Issac,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
+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

python-sqlite-sqlalchemy/build_data/data/author_book_publisher.db

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+name,2019-01-02,2019-01-09,2019-01-16,2019-01-23,2019-01-30,2019-02-06,2019-02-13,2019-02-20,2019-02-27,2019-03-06,2019-03-13,2019-03-20,2019-03-27,2019-04-03,2019-04-10,2019-04-17,2019-04-24,2019-05-01,2019-05-08,2019-05-15,2019-05-22,2019-05-29,2019-06-05,2019-06-12,2019-06-19,2019-06-26,2019-07-03,2019-07-10,2019-07-17,2019-07-24,2019-07-31,2019-08-07,2019-08-14,2019-08-21,2019-08-28,2019-09-04,2019-09-11,2019-09-18,2019-09-25,2019-10-02,2019-10-09,2019-10-16,2019-10-23,2019-10-30,2019-11-06,2019-11-13,2019-11-20,2019-11-27,2019-12-04,2019-12-11,2019-12-18,2019-12-25
+John,4,17,13,18,19,17,22,16,34,36,29,28,28,41,40,40,40,39,56,48,55,63,58,61,63,78,71,79,87,76,93,86,84,81,84,93,91,71,77,71,65,62,68,69,74,62,68,38,45,33,34,36
+Mary,12,21,11,29,12,21,16,25,18,34,26,26,31,38,28,30,38,37,54,42,48,50,68,67,74,75,86,75,85,83,94,95,86,80,88,95,89,73,87,80,79,65,65,67,60,71,69,48,45,43,23,24
+Susan,7,18,22,22,6,11,7,20,17,36,32,33,27,33,42,33,44,47,46,43,50,63,63,65,73,71,71,89,77,76,79,93,95,89,87,94,92,80,82,73,65,63,77,63,64,70,69,54,45,38,21,34
+Doug,18,15,14,15,17,18,15,22,18,37,32,36,27,35,27,50,39,40,54,44,62,57,71,74,62,75,74,74,86,82,79,79,92,97,99,82,74,71,87,65,74,72,66,73,64,58,68,49,39,39,29,29
+Andrew,5,4,20,16,12,14,8,16,31,29,35,38,30,38,35,47,46,50,60,51,62,50,72,69,68,82,80,72,72,81,85,81,90,87,86,83,78,84,82,81,62,79,66,68,56,69,51,45,36,30,37,34
+George,17,14,15,26,18,22,17,13,32,31,36,31,46,44,32,35,34,47,43,47,62,70,75,63,64,65,76,71,75,83,78,88,88,88,99,75,86,91,80,72,79,80,60,64,71,70,51,51,36,28,37,22
+Martha,0,4,11,27,19,22,13,24,28,25,37,35,29,43,35,37,39,42,57,53,68,69,69,67,70,68,83,87,74,79,95,94,85,87,81,89,81,89,85,68,78,62,61,55,57,55,70,43,40,31,31,29
+Paul,1,20,15,27,11,20,12,29,26,30,27,29,40,34,45,45,45,51,51,46,68,56,67,73,66,79,77,88,85,83,88,79,81,81,98,76,89,76,86,73,63,70,72,68,61,62,67,35,39,35,26,31
+Helen,17,15,18,15,4,15,16,21,28,24,32,35,35,29,28,43,54,40,41,60,60,63,65,74,79,74,82,72,78,81,86,86,81,90,91,86,83,80,80,81,80,67,75,73,58,52,51,37,38,46,34,26