I have such Python code:

```
import numpy as np
import matplotlib.pyplot as plt
def f(x):
return np.int(x)
x = np.arange(1, 15.1, 0.1)
plt.plot(x, f(x))
plt.show()
```

And such error:

```
TypeError: only length-1 arrays can be converted to Python scalars
```

How can I fix it?

## Solution

The error "only length-1 arrays can be converted to Python scalars" is raised when the function expects a single value but you pass an array instead.

`np.int`

was an alias for the built-in `int`

, which is deprecated in numpy v1.20. The argument for int should be a scalar and it does not accept array-like objects. In general, if you want to apply a function to each element of the array, you can use `np.vectorize`

:

```
import numpy as np
import matplotlib.pyplot as plt
def f(x):
return int(x)
f2 = np.vectorize(f)
x = np.arange(1, 15.1, 0.1)
plt.plot(x, f2(x))
plt.show()
```

You can skip the definition of f(x) and just pass the function `int`

to the vectorize function: `f2 = np.vectorize(int)`

.

Note that `np.vectorize`

is just a convenience function and basically a for loop. That will be inefficient over large arrays. Whenever you have the possibility, use truly vectorized functions or methods (like `astype(int)`

as @FFT suggests).

Source: StackOverflow.com