Development

.gitignore

@@ -1,3 +1,5 @@
+temp_pictures/
+
 # Byte-compiled / optimized / DLL files
 __pycache__/
 *.py[cod]
@@ -101,4 +103,4 @@ ENV/
 .mypy_cache/
 
 # pycharm files
-.idea/
+.idea/

.vscode/settings.json

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+{
+    "python.pythonPath": "venv/bin/python3.7"
+}

README.md

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 # wswp-ask-mate
 Web and SQL with Python / 1st TW week / Ask Mate project
+
+please run >>>>>>>>>>>>>>>>>>         pip install -r requirements.txt
+
+Presentation: 1st week https://docs.google.com/presentation/d/1su5RmQHdyfDgrQiKhYdD0PO9AavsXH64DfdY59Jnf3A/edit?usp=sharing

connection.py

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+# Creates a decorator to handle the database connection/cursor opening/closing.
+# Creates the cursor with RealDictCursor, thus it returns real dictionaries, where the column names are the keys.
+import os
+import psycopg2
+import psycopg2.extras
+
+
+def get_connection_string():
+    # setup connection string
+    # to do this, please define these environment variables first
+    user_name = os.environ.get('PSQL_USER_NAME')
+    password = os.environ.get('PSQL_PASSWORD')
+    host = os.environ.get('PSQL_HOST')
+    database_name = os.environ.get('PSQL_DB_NAME')
+
+    env_variables_defined = user_name and password and host and database_name
+
+    if env_variables_defined:
+        # this string describes all info for psycopg2 to connect to the database
+        return 'postgresql://{user_name}:{password}@{host}/{database_name}'.format(
+            user_name=user_name,
+            password=password,
+            host=host,
+            database_name=database_name
+        )
+    else:
+        raise KeyError('Some necessary environment variable(s) are not defined')
+
+
+def open_database():
+    try:
+        connection_string = get_connection_string()
+        connection = psycopg2.connect(connection_string)
+        connection.autocommit = True
+    except psycopg2.DatabaseError as exception:
+        print('Database connection problem')
+        raise exception
+    return connection
+
+
+def connection_handler(function):
+    def wrapper(*args, **kwargs):
+        connection = open_database()
+        # we set the cursor_factory parameter to return with a RealDictCursor cursor (cursor which provide dictionaries)
+        dict_cur = connection.cursor(cursor_factory=psycopg2.extras.RealDictCursor)
+        ret_value = function(dict_cur, *args, **kwargs)
+        dict_cur.close()
+        connection.close()
+        return ret_value
+
+    return wrapper