Upload Mission251 solutions

Mission251Solutions.py

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+import csv
+from datetime import datetime
+import io
+import psycopg2
+from urllib import request
+
+
+conn = psycopg2.connect(dbname='postgres', user='postgres')
+cur = conn.cursor()
+# Autocommit instead of commiting every transaction.
+conn.autocommit = True
+
+# Create database and users.
+cur.execute('CREATE DATABASE ihw')
+cur.execute("CREATE USER production WITH PASSWORD 'abc123'")
+cur.execute("CREATE USER analyst WITH PASSWORD 'def456'")
+
+# Reconnect to ihw database.
+conn = psycopg2.connect(dbname='ihw', user='postgres')
+conn.autocommit = True
+cur = conn.cursor()
+
+# Create the table.
+cur.execute(
+    """
+    CREATE TABLE hurricanes (
+        fid INTEGER PRIMARY KEY,
+        recorded_at TIMESTAMP,
+        btid INTEGER,
+        name VARCHAR(10),
+        lat DECIMAL(4, 1),
+        long DECIMAL(4, 1),
+        wind_kts SMALLINT,
+        pressure INTEGER,
+        category VARCHAR(2),
+        basin VARCHAR(16),
+        shape_length DECIMAL(8, 6)
+    )
+    """
+)
+
+# Manage privileges.
+cur.execute("REVOKE ALL ON hurricanes FROM production")
+cur.execute("REVOKE ALL ON hurricanes FROM analyst")
+cur.execute("GRANT SELECT, INSERT, UPDATE ON hurricanes TO production")
+cur.execute("GRANT SELECT ON hurricanes TO analyst")
+conn.close()
+
+# Reconnect with production user.
+conn = psycopg2.connect(dbname='ihw', user='production', password='abc123')
+cur = conn.cursor()
+conn.autocommit = True
+
+# Insert the data.
+response = request.urlopen('https://dq-content.s3.amazonaws.com/251/storm_data.csv')
+reader = csv.reader(io.TextIOWrapper(response))
+# Skip the header.
+_ = next(reader)
+rows = []
+for line in reader:
+    recorded_at = datetime(int(line[1]), int(line[2]), int(line[3]), hour=int(line[4][:2]), minute=int(line[4][2:-1]))
+
+    new_line = [line[0], recorded_at] + line[5:]
+    rows.append(
+        cur.mogrify(
+            "(%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)",
+            new_line
+        ).decode('utf-8')
+    )
+cur.execute('INSERT INTO hurricanes VALUES ' + ",".join(rows))