# Importing Brian2¶

After installation, Brian2 is avaiable in the `brian2` package. By doing a
wildcard import from this package, i.e.:

```
from brian2 import *
```

you will not only get access to the `brian2` classes and functions, but also
to everything in the `pylab` package, which includes the plotting functions
from matplotlib and everything included in numpy/scipy (e.g. functions such
as `arange`, `linspace`, etc.). This is the style used in the documentation
and in the examples but not in the Brian2 code itself (see
*Coding conventions*).

If you want to use a wildcard import from Brian2, but don’t want to import all
the additional symbols provided by `pylab`, you can use:

```
from brian2.only import *
```

Note that whenever you use something different from the most general
`from brian2 import *` statement, you should be aware that Brian2 overwrites
some numpy functions with their unit-aware equivalents
(see *Units*). If you combine multiple wildcard imports, the
Brian2 import should therefore be the last import. Similarly, you should not
import and call overwritten numpy functions directly, e.g. by using
`import numpy as np` followed by `np.sin` since this will not use the
unit-aware versions. To make this easier, Brian2 provides a `brian2.numpy_`
package that provides access to everything in numpy but overwrites certain
functions. If you prefer to use prefixed names, the recommended way of doing
the imports is therefore:

```
import brian2.numpy_ as np
import brian2.only as br2
```

Note that it is safe to use e.g. `np.sin` and `numpy.sin` after a
`from brian2 import *`.