mongodbshell 0.1a3

# mongodbshell - A utility class for the Python Shell

the Python shell is the ideal environment for Python developers to interact
with MongoDB. However output cursors and interacting with the database requires
a little more boilerplate than is convenient. the `mongodbshell` package
provides a set a convenience functions and objects to allow easier
interaction with MongoDB via the Python interpreter.

The easiest way to get started with `mongodbshell` is to import the prebuilt
`mproxy` object. The `mproxy` object expects to connect to a `mongod` running
locally on port 27017 (it uses the [MongoDB URI](https://docs.mongodb.com/manual/reference/connection-string/)
`mongodb://localhost:27017` by default)

```python
$ python3
Python 3.6.5 (v3.6.5:f59c0932b4, Mar 28 2018, 03:03:55)
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from mongodbshell import mproxy
>>> mproxy
Proxy('test', 'test', 'mongodb://localhost:27017')
>>> mproxy.list_database_names()
1 config
2 test
3 local
4 admin
>>>
```
Each proxy object has host of standard properties:
```python
>>> mproxy.client
MongoClient(host=['localhost:27017'], document_class=dict, tz_aware=False, connect=True)
>>> mproxy.database
Database(MongoClient(host=['localhost:27017'], document_class=dict, tz_aware=False, connect=True), 'test')
>>> mproxy.collection
Collection(Database(MongoClient(host=['localhost:27017'], document_class=dict, tz_aware=False, connect=True), 'test'), 'test')
>>> mproxy.uri
'mongodb://localhost:27017'
>>>
```

There are also convenience functions for the most popular operations:

```python
>>> mproxy.is_master()
{'ismaster': True,
'localTime': datetime.datetime(2019, 1, 16, 15, 15, 41, 87000),
'logicalSessionTimeoutMinutes': 30,
'maxBsonObjectSize': 16777216,
'maxMessageSizeBytes': 48000000,
'maxWireVersion': 7,
'maxWriteBatchSize': 100000,
'minWireVersion': 0,
'ok': 1.0,
'readOnly': False}
>>> mproxy.insert_one({"name" : "Joe Drumgoole", "twitter_handle" : "@jdrumgoole"})
ObjectId('5c3f4f2fc3b498d6674b08f0')
>>> mproxy.find_one( {"name" : "Joe Drumgoole"})
1 {'_id': ObjectId('5c3f4b04c3b498d4a1c6ce22'),
2 'name': 'Joe Drumgoole',
3 'twitter_handle': '@jdrumgoole'}
```

## Line Numbers on Output

Line numbers are added to output by default. You can turn off line numbers by
setting the `line_numbers` flag to false.

```python
>>> mproxy.insert_one({"name" : "Joe Drumgoole", "twitter_handle" : "@jdrumgoole"})
ObjectId('5c3f4f2fc3b498d6674b08f0')
>>> mproxy.find_one( {"name" : "Joe Drumgoole"})
1 {'_id': ObjectId('5c3f4b04c3b498d4a1c6ce22'),
2 'name': 'Joe Drumgoole',
3 'twitter_handle': '@jdrumgoole'}
>>> mproxy.line_numbers = False # Turn off line numbers
>>> mproxy.find_one( {"name" : "Joe Drumgoole"})
{'_id': ObjectId('5c3f4b04c3b498d4a1c6ce22'),
'name': 'Joe Drumgoole',
'twitter_handle': '@jdrumgoole'}
>>>
```
## Connecting to a specific MongoDB URI

You can connect to a different database by using the `Proxy` class. Here is an
example connection to a [MongoDB Atlas](https://www.mongodb.com/cloud/atlas) hosted datbase.

```python
>>> from mongodbshell import Proxy
>>> atlas=Proxy(uri="mongodb+srv://readonly:readonly@demodata-rgl39.mongodb.net/test?retryWrites=true", database="demo", collection="zipcodes")
>>> atlas.find_one()
1 {'_id': '01069',
2 'city': 'PALMER',
3 'loc': [-72.328785, 42.176233],
4 'pop': 9778,
5 'state': 'MA'}

```

## Looking at large volumes of output

If you run a query in the python shell it will return a cursor and to look at
the objects in the cursor you need to either write a loop to consume the cursor
or explicitly call `next()` on each cursor item.

```python
>>> c=pymongo.MongoClient("mongodb+srv://readonly:readonly@demodata-rgl39.mongodb.net/test?retryWrites=true")
>>> db=c["demo"]
>>> collection=db["zipcodes"]
>>> collection.find()
<pymongo.cursor.Cursor object at 0x105bf1d68>
>>> cursor=collection.find()
>>> next(cursor)
{'_id': '01069', 'city': 'PALMER', 'loc': [-72.328785, 42.176233], 'pop': 9778, 'state': 'MA'}
>>> next(cursor)
{'_id': '01002', 'city': 'CUSHMAN', 'loc': [-72.51565, 42.377017], 'pop': 36963, 'state': 'MA'}
>>>
```

This is tedious and becomes even more so when the objects are large enough to
scroll off the screen. This is not a problem with the `mongodbshell` as the
`Proxy` class and the built in `mproxy` object automatically handle
pretty printing and paginating outing.

```python
>>> atlas.find()
1 {'_id': '01069', 'city': 'PALMER', 'loc': [-72.328785, 42.176233], 'pop': 9778, 'state': 'MA'}
2 {'_id': '01002', 'city': 'CUSHMAN', 'loc': [-72.51565, 42.377017], 'pop': 36963, 'state': 'MA'}
3 {'_id': '01012', 'city': 'CHESTERFIELD', 'loc': [-72.833309, 42.38167], 'pop': 177, 'state': 'MA'}
4 {'_id': '01073', 'city': 'SOUTHAMPTON', 'loc': [-72.719381, 42.224697], 'pop': 4478, 'state': 'MA'}
5 {'_id': '01096', 'city': 'WILLIAMSBURG', 'loc': [-72.777989, 42.408522], 'pop': 2295, 'state': 'MA'}
6 {'_id': '01262', 'city': 'STOCKBRIDGE', 'loc': [-73.322263, 42.30104], 'pop': 2200, 'state': 'MA'}
7 {'_id': '01240', 'city': 'LENOX', 'loc': [-73.271322, 42.364241], 'pop': 5001, 'state': 'MA'}
8 {'_id': '01370', 'city': 'SHELBURNE FALLS', 'loc': [-72.739059, 42.602203], 'pop': 4525, 'state': 'MA'}
9 {'_id': '01340', 'city': 'COLRAIN', 'loc': [-72.726508, 42.67905], 'pop': 2050, 'state': 'MA'}
10 {'_id': '01462', 'city': 'LUNENBURG', 'loc': [-71.726642, 42.58843], 'pop': 9117, 'state': 'MA'}
11 {'_id': '01473', 'city': 'WESTMINSTER', 'loc': [-71.909599, 42.548319], 'pop': 6191, 'state': 'MA'}
12 {'_id': '01510', 'city': 'CLINTON', 'loc': [-71.682847, 42.418147], 'pop': 13269, 'state': 'MA'}
13 {'_id': '01569', 'city': 'UXBRIDGE', 'loc': [-71.632869, 42.074426], 'pop': 10364, 'state': 'MA'}
14 {'_id': '01775', 'city': 'STOW', 'loc': [-71.515019, 42.430785], 'pop': 5328, 'state': 'MA'}
Hit Return to continue (q or quit to exit)
```
Pagination will dynamically adjust to screen height.

## Outputting to a file

The `Proxy` class can send output to a file by setting the `output_file` property
on the `Proxy` class.

```python
>>> atlas.output_file="zipcodes.txt"
>>> atlas.find()
Output is also going to 'zipcodes.txt'
1 {'_id': '01069', 'city': 'PALMER', 'loc': [-72.328785, 42.176233], 'pop': 9778, 'state': 'MA'}
2 {'_id': '01002', 'city': 'CUSHMAN', 'loc': [-72.51565, 42.377017], 'pop': 36963, 'state': 'MA'}
3 {'_id': '01012', 'city': 'CHESTERFIELD', 'loc': [-72.833309, 42.38167], 'pop': 177, 'state': 'MA'}
4 {'_id': '01073', 'city': 'SOUTHAMPTON', 'loc': [-72.719381, 42.224697], 'pop': 4478, 'state': 'MA'}
5 {'_id': '01096', 'city': 'WILLIAMSBURG', 'loc': [-72.777989, 42.408522], 'pop': 2295, 'state': 'MA'}
6 {'_id': '01262', 'city': 'STOCKBRIDGE', 'loc': [-73.322263, 42.30104], 'pop': 2200, 'state': 'MA'}
7 {'_id': '01240', 'city': 'LENOX', 'loc': [-73.271322, 42.364241], 'pop': 5001, 'state': 'MA'}
8 {'_id': '01370', 'city': 'SHELBURNE FALLS', 'loc': [-72.739059, 42.602203], 'pop': 4525, 'state': 'MA'}
9 {'_id': '01340', 'city': 'COLRAIN', 'loc': [-72.726508, 42.67905], 'pop': 2050, 'state': 'MA'}
10 {'_id': '01462', 'city': 'LUNENBURG', 'loc': [-71.726642, 42.58843], 'pop': 9117, 'state': 'MA'}
11 {'_id': '01473', 'city': 'WESTMINSTER', 'loc': [-71.909599, 42.548319], 'pop': 6191, 'state': 'MA'}
12 {'_id': '01510', 'city': 'CLINTON', 'loc': [-71.682847, 42.418147], 'pop': 13269, 'state': 'MA'}
13 {'_id': '01569', 'city': 'UXBRIDGE', 'loc': [-71.632869, 42.074426], 'pop': 10364, 'state': 'MA'}
14 {'_id': '01775', 'city': 'STOW', 'loc': [-71.515019, 42.430785], 'pop': 5328, 'state': 'MA'}
>>> print(open('zipcodes.txt').read())
{'_id': '01069', 'city': 'PALMER', 'loc': [-72.328785, 42.176233], 'pop': 9778, 'state': 'MA'}
{'_id': '01002', 'city': 'CUSHMAN', 'loc': [-72.51565, 42.377017], 'pop': 36963, 'state': 'MA'}
{'_id': '01012', 'city': 'CHESTERFIELD', 'loc': [-72.833309, 42.38167], 'pop': 177, 'state': 'MA'}
{'_id': '01073', 'city': 'SOUTHAMPTON', 'loc': [-72.719381, 42.224697], 'pop': 4478, 'state': 'MA'}
{'_id': '01096', 'city': 'WILLIAMSBURG', 'loc': [-72.777989, 42.408522], 'pop': 2295, 'state': 'MA'}
{'_id': '01262', 'city': 'STOCKBRIDGE', 'loc': [-73.322263, 42.30104], 'pop': 2200, 'state': 'MA'}
{'_id': '01240', 'city': 'LENOX', 'loc': [-73.271322, 42.364241], 'pop': 5001, 'state': 'MA'}
{'_id': '01370', 'city': 'SHELBURNE FALLS', 'loc': [-72.739059, 42.602203], 'pop': 4525, 'state': 'MA'}
{'_id': '01340', 'city': 'COLRAIN', 'loc': [-72.726508, 42.67905], 'pop': 2050, 'state': 'MA'}
{'_id': '01462', 'city': 'LUNENBURG', 'loc': [-71.726642, 42.58843], 'pop': 9117, 'state': 'MA'}
{'_id': '01473', 'city': 'WESTMINSTER', 'loc': [-71.909599, 42.548319], 'pop': 6191, 'state': 'MA'}
{'_id': '01510', 'city': 'CLINTON', 'loc': [-71.682847, 42.418147], 'pop': 13269, 'state': 'MA'}
{'_id': '01569', 'city': 'UXBRIDGE', 'loc': [-71.632869, 42.074426], 'pop': 10364, 'state': 'MA'}
{'_id': '01775', 'city': 'STOW', 'loc': [-71.515019, 42.430785], 'pop': 5328, 'state': 'MA'}
```
Output will continue to be sent to the `output_file` until the output_file is assigned
`None` or the empty string ("").

## Options

You can set the following options on the `mproxy` or `Proxy` class objects.

`proxy.line_numbers` : Bool. True to display line numbers in output, False to
remove them.

`proxy.pretty_print` : Bool. True to use `pprint.pprint` to output documents.
False to write them out as the database returned them.

`proxy.paginate` : Bool. True to paginate output based on screen height. False to just
send all output directly to console.

`proxy.output_file` : Str. Define a file to write results to. All output is
appended to the file. Each line is flushed so content is not lost. Set `output_file`
ton `None` or the emtpy string ("") to stop output going to a file.