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--- pythonpostgresql [2021/11/29 14:15] – created z0hpvk
+++ pythonpostgresql [2025/03/08 22:24] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
-==== psychopg ====
+==== psycopg ====
+[[https://www.psycopg.org/|psycopg Homepage]]\\
+[[https://pypi.org/project/psycopg2/|psycopg2 Installation]]\\
+=== Connecting to PostgreSQL ===
+<code python>
+import psycopg2
+import psycopg2.extras
+conn = psycopg2.connect(database="doob", user = "ian", password = "pwd", host = "localhost")
+print "Connection Successful"
+#cur = conn.cursor()
+cur = conn.cursor(cursor_factory=psycopg2.extras.DictCursor)
+query = "SELECT usename, usesuper FROM pg_user"
+cur.execute(query)
+rows = cur.fetchall()
+for row in rows:
+  print(row)
+  print(f"{row['usename']} {row['usesuper']}")
+cur.close()
+</code>
+=== Example Connection Files ===
+== Using Config Parser ==
+<code python>
+# database.ini
+[postgresql]
+host=localhost
+database=doob
+user=ian
+password=pwd
+</code>
+<code python>
+#!/usr/bin/python
+from configparser import ConfigParser
+def config(filename='database.ini', section='postgresql'):
+  parser = ConfigParser()
+  parser.read(filename)
+  params = parser.items(section)
+  for param in params:
+    db[param[0]] = param[1]
+  return db
+</code>
+<code python>
+#!/usr/bin/python
+from config import config
+def connect()
+  conn = None
+  try:
+    params = config()
+    conn = psycopg2.connect(**params)
+    cur = conn.cursor()
+    cur.execute('SELECT version()')
+    db_version = cur.fetchone()
+    print(db_version)
+    cur.close()
+  except (Exception, psycopg2.DatabaseError) as error:
+    print(error)
+</code>
+== Using Credential File ==
+<code python>
+# conndetails.py
+PGHOST="localhost"
+PGDATABASE="doob"
+PGUSER="ian"
+PGPASSWORD="pwd"
+</code>
+<code python>
+import psycopg2
+import conndetails as creds
+conn_string = "host="+ creds.PGHOST +" dbname="+ creds.PGDATABASE +" user="
+               + creds.PGUSER +" password="+ creds.PGPASSWORD
+conn = psycopg2.connect(conn_string)
+cur = conn.cursor()
+query = "select version()"
+cur.execute(query)
+for row in cur:
+  print(row)
+cur.close()
+</code>