
The standard way to import NumPy:

```python
>>> import numpy as np
```

Create a 2-D array, set every second element in some rows, and find max per
row:

```python
>>> x = np.arange(15, dtype=np.int64).reshape(3, 5)
>>> x[1:, ::2] = -99
>>> x
array([[  0,   1,   2,   3,   4],
       [-99,   6, -99,   8, -99],
       [-99,  11, -99,  13, -99]])
>>> x.max(axis=1)
array([ 4,  8, 13])
```

Generate some random numbers with an exponential distribution:
```python
>>> rng = np.random.default_rng()
>>> samples = rng.exponential(size=2500)
```

```python
>>> # The standard way to import NumPy:
>>> import numpy as np

>>> # Create a 2-D array, set every second element in
>>> # some rows and find max per row:

>>> x = np.arange(15, dtype=np.int64).reshape(3, 5)
>>> x[1:, ::2] = -99
>>> x
array([[  0,   1,   2,   3,   4],
       [-99,   6, -99,   8, -99],
       [-99,  11, -99,  13, -99]])
>>> x.max(axis=1)
array([ 4,  8, 13])

>>> # Generate normally distributed random numbers:
>>> rng = np.random.default_rng()
>>> samples = rng.normal(size=2500)
```

Make example in interactive shell copy-pastable.
Make example in interactive shell copy-pastable.

Closes gh-240
