---
id: diagram
title: Diagrams
---
Diagram is a primary object representing a diagram.
## Basic
Diagram represents a global diagram context.
You can create a diagram context with Diagram class. The first parameter of Diagram constructor will be used for output filename.
```python
from diagrams import Diagram
from diagrams.aws.compute import EC2
with Diagram("Simple Diagram"):
EC2("web")
```
And if you run the above script with below command,
```shell
$ python diagram.py
```
It will generate an image file with single `EC2` node drawn as `simple_diagram.png` on your working directory, and open that created image file immediately.
## Jupyter Notebooks
Diagrams can be also rendered directly inside the notebook as like this:
```python
from diagrams import Diagram
from diagrams.aws.compute import EC2
with Diagram("Simple Diagram") as diag:
EC2("web")
diag
```
## Options
You can specify the output file format with `outformat` parameter. Default is **png** .
> (png, jpg, svg, and pdf) are allowed.
```python
from diagrams import Diagram
from diagrams.aws.compute import EC2
with Diagram("Simple Diagram", outformat="jpg"):
EC2("web")
```
You can specify the output filename with `filename` parameter. The extension shouldn't be included, it's determined by the `outformat` parameter.
```python
from diagrams import Diagram
from diagrams.aws.compute import EC2
with Diagram("Simple Diagram", filename="my_diagram"):
EC2("web")
```
You can also disable the automatic file opening by setting the `show` parameter as **false** . Default is **true** .
```python
from diagrams import Diagram
from diagrams.aws.compute import EC2
with Diagram("Simple Diagram", show=False):
EC2("web")
```
It allows custom Graphviz dot attributes options.
> `graph_attr`, `node_attr` and `edge_attr` are supported. Here is a [reference link](https://www.graphviz.org/doc/info/attrs.html).
```python
from diagrams import Diagram
from diagrams.aws.compute import EC2
graph_attr = {
"fontsize": "45",
"bgcolor": "transparent"
}
with Diagram("Simple Diagram", show=False, graph_attr=graph_attr):
EC2("web")
```
