Psycopg is the most popular PostgreSQL database adapter for Python. Its main features are the complete implementation of the Python DB API 2.0 specification and the thread safety (several threads can share the same connection). YugabyteDB has full support for [Psycopg2](https://www.psycopg.org/).
## CRUD operations
The following sections demonstrate how to perform common tasks required for Python application development using the PostgreSQL Psycopg2 driver.
To start building your application, make sure you have met the [prerequisites](../#prerequisites).
### Step 1: Download the driver dependency
Building Psycopg requires a few prerequisites (a C compiler, some development packages). Refer to [Installation](https://www.psycopg.org/docs/install.html#install-from-source) and the [FAQ](https://www.psycopg.org/docs/faq.html#faq-compile) in the Psycopg documentation.
If prerequisites are met, you can install psycopg like any other Python package, using `pip` to download it from [PyPI](https://pypi.org/project/psycopg2/):
```sh
$ pip install psycopg2
```
or, using `setup.py`, if you have downloaded the source package locally:
```sh
python setup.py build
sudo python setup.py install
```
You can also obtain a stand-alone package, not requiring a compiler or external libraries, by installing the [psycopg2-binary](https://pypi.org/project/psycopg2-binary/) package from PyPI:
```sh
pip install psycopg2-binary
```
The binary package is a practical choice for development and testing, but in production it is recommended to use the package built from sources.
### Step 2: Connect to your cluster
The following table describes the connection parameters required to connect.
| Parameter | Description | Default |
| :---------- | :---------- | :------ |
| host | Hostname of the YugabyteDB instance | localhost
| port | Listen port for YSQL | 5433
| database/dbname | Database name | yugabyte
| user | User connecting to the database | yugabyte
| password | User password | yugabyte
You can provide the connection details in one of the following ways:
- Connection string
```python
"dbname=database_name host=hostname port=port user=username password=password"
```
- Connection dictionary
```python
user = 'username', password='xxx', host = 'hostname', port = 'port', dbname = 'database_name'
```
The following is an example connection string for connecting to YugabyteDB.
```python
conn = psycopg2.connect(dbname='yugabyte',host='localhost',port='5433',user='yugabyte',password='yugabyte')
```
#### Use SSL
The following table describes the connection parameters required to connect using SSL.
| Parameter | Description | Default |
| :-------- | :---------- | :------ |
| sslmode | SSL mode | prefer
| sslrootcert | Path to the root certificate on your computer | ~/.postgresql/
The following is an example for connecting to YugabyteDB with SSL encryption enabled:
```python
conn = psycopg2.connect("host= port=5433 dbname=yugabyte user= password= sslmode=verify-full sslrootcert=/Users/my-user/Downloads/root.crt")
```
If you have created a cluster on YugabyteDB Aeon, use the cluster credentials and [download the SSL Root certificate](/stable/yugabyte-cloud/cloud-secure-clusters/cloud-authentication/#download-your-cluster-certificate).
### Step 3: Write your application
Create a new Python file called `QuickStartApp.py` in the base package directory of your project.
Copy the following sample code to set up tables and query the table contents. Replace the connection string `connString` with the cluster credentials and SSL certificate, if required.
```python
import psycopg2
# Create the database connection.
connString = "host=127.0.0.1 port=5433 dbname=yugabyte user=yugabyte password=yugabyte"
conn = psycopg2.connect(connString)
# Open a cursor to perform database operations.
# The default mode for psycopg2 is "autocommit=false".
conn.set_session(autocommit=True)
cur = conn.cursor()
# Create the table. (It might preexist.)
cur.execute(
"""
DROP TABLE IF EXISTS employee
""")
cur.execute(
"""
CREATE TABLE employee (id int PRIMARY KEY,
name varchar,
age int,
language varchar)
""")
print("Created table employee")
cur.close()
# Take advantage of ordinary, transactional behavior for DMLs.
conn.set_session(autocommit=False)
cur = conn.cursor()
# Insert a row.
cur.execute("INSERT INTO employee (id, name, age, language) VALUES (%s, %s, %s, %s)",
(1, 'John', 35, 'Python'))
print("Inserted (id, name, age, language) = (1, 'John', 35, 'Python')")
# Query the row.
cur.execute("SELECT name, age, language FROM employee WHERE id = 1")
row = cur.fetchone()
print("Query returned: %s, %s, %s" % (row[0], row[1], row[2]))
# Commit and close down.
conn.commit()
cur.close()
conn.close()
```
Run the project `QuickStartApp.py` using the following command:
```python
python3 QuickStartApp.py
```
You should see output similar to the following:
```text
Created table employee
Inserted (id, name, age, language) = (1, 'John', 35, 'Python')
Query returned: John, 35, Python
```
If there is no output or you get an error, verify the parameters included in the connection string.
### Limitations
Currently, [PostgreSQL psycopg2 driver](https://github.com/psycopg/psycopg2) and [Yugabyte Psycopg2 smart driver](https://github.com/yugabyte/psycopg2) _cannot_ be used in the same environment.
## Learn more
[YugabyteDB smart drivers for YSQL](../../smart-drivers/)
Yugabyte Psycopg2