# Convert ndarray from float64 to integer

## Question:

I’ve got an `ndarray`

in python with a `dtype`

of `float64`

. I’d like to convert the array to be an array of integers. How should I do this?

`int()`

won’t work, as it says it can’t convert it to a scalar. Changing the `dtype`

field itself obviously doesn’t work, as the actual bytes haven’t changed. I can’t seem to find anything on Google or in the documentation – what’s the best way to do this?

## Answers:

Use `.astype`

.

```
>>> a = numpy.array([1, 2, 3, 4], dtype=numpy.float64)
>>> a
array([ 1., 2., 3., 4.])
>>> a.astype(numpy.int64)
array([1, 2, 3, 4])
```

See the documentation for more options.

There’s also a really useful discussion about converting the array in place, In-place type conversion of a NumPy array. If you’re concerned about copying your array (which is what`astype()`

does) definitely check out the link.

While `astype`

is probably the “best” option there are several other ways to convert it to an integer array. I’m using this `arr`

in the following examples:

```
>>> import numpy as np
>>> arr = np.array([1,2,3,4], dtype=float)
>>> arr
array([ 1., 2., 3., 4.])
```

## The `int*`

functions from NumPy

```
>>> np.int64(arr)
array([1, 2, 3, 4])
>>> np.int_(arr)
array([1, 2, 3, 4])
```

## The NumPy `*array`

functions themselves:

```
>>> np.array(arr, dtype=int)
array([1, 2, 3, 4])
>>> np.asarray(arr, dtype=int)
array([1, 2, 3, 4])
>>> np.asanyarray(arr, dtype=int)
array([1, 2, 3, 4])
```

## The `astype`

method (that was already mentioned but for completeness sake):

```
>>> arr.astype(int)
array([1, 2, 3, 4])
```

Note that passing `int`

as dtype to `astype`

or `array`

will default to a default integer type that depends on your platform. For example on Windows it will be `int32`

, on 64bit Linux with 64bit Python it’s `int64`

. If you need a specific integer type and want to avoid the platform “ambiguity” you should use the corresponding NumPy types like `np.int32`

or `np.int64`

.

All I used is

```
numpyfloat = (1.0, 2.0, 4.0)
a = numpy.array(numpyfloat, dtype=numpy.int)
```

That’s just it