# Python Dbm Module

The `dbm` module provides a generic interface to variants of the DBM database — `dbm.gnu` or `dbm.ndbm`. If none of these modules is installed, the slow-but-simple implementation `dbm.dumb` will be used. It behaves like a dictionary, but keys and values are stored in a file.

## Importing the Module

```python
import dbm
```

## Opening a Database

To open a database, use `dbm.open()`. The flags are `'r'` (read), `'w'` (write), `'c'` (create), `'n'` (new/overwrite).

```python
import dbm

# Open database, creating it if necessary
with dbm.open('cache', 'c') as db:
    # ... use the database ...
    pass
```

## Writing Data

Data is stored by assigning a value to a key. Keys and values must be strings or bytes.

```python
import dbm

with dbm.open('cache', 'c') as db:
    db['user'] = 'admin'
    db['www.python.org'] = '127.0.0.1'
```

## Reading Data

You can access data using the key. Note that values are returned as bytes.

```python
import dbm

with dbm.open('cache', 'r') as db:
    print(db.get('user')) # Output: b'admin'
    
    if 'www.python.org' in db:
        print(db['www.python.org']) # Output: b'127.0.0.1'
```

## Iterating

You can iterate over keys in the database.

```python
import dbm

with dbm.open('cache', 'r') as db:
    for key in db.keys():
        print(key)
```

[[programming/python/python]]