Python 'AttributeError: 'function' object has no attribute 'min''

Question

Firstly, apologies for how obvious these two questions seem to be; I\'m very very new to this and don\'t have a clue what I\'m doing.

I\'m trying to write something to a

Answer 1

If this line

new_x = np.linspace(x.min(), x.max(), new_length)

is generating the error message

AttributeError: 'function' object has no attribute 'min'

then x is a function, and functions (in general) don't have min attributes, so you can't call some_function.min(). What is x? In your code, you've only defined it as

x=var

I'm not sure what var is. var isn't a default builtin in Python, but if it's a function, then either you've defined it yourself for some reason or you've picked it up from somewhere (say you're using Sage, or you did a star import like from sympy import * or something.)

[Update: since you say you're "using PyLab", probably var is numpy.var which has been imported into scope at startup in IPython. I think you really mean "using IPython in --pylab mode.]

You also define x1 and y1, but then your later code refers to x and y, so it sort of feels like this code is halfway between two functional states.

Now numpy arrays do have a .min() and .max() method, so this:

>>> x = np.array([0.1, 0.3, 0.4, 0.7])
>>> y = np.array([0.2, 0.5, 0.6, 0.9])
>>> new_length = 25
>>> new_x = np.linspace(x.min(), x.max(), new_length)
>>> new_y = sp.interpolate.interp1d(x, y, kind='cubic')(new_x)

would work. Your test data won't because the interpolation needs at least 4 points, and you'd get

ValueError: x and y arrays must have at least 4 entries

Answer 2

Second question: how do I input more than one line of code at once? At the moment, if I try to copy the whole thing and then paste it into PyLab, it only inputs the top line of my code, so I have to paste the whole thing in one line at a time. How do I get round this?

Assuming you're in ipython called as ipython --pylab or something similar, then you can simply use the paste magic command. Call it as %paste or simply paste if you haven't defined paste as another variable:

In [8]: paste
import numpy as np
import scipy as sp
from scipy.interpolate import interp1d

x=var
x1 = ([0.1,0.3,0.4])
y1 = [0.2,0.5,0.6]

new_length = 25
new_x = np.linspace(x.min(), x.max(), new_length)
new_y = sp.interpolate.interp1d(x, y, kind='cubic')(new_x)

## -- End pasted text --
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-8-b4e41f59d719> in <module>()
      3 from scipy.interpolate import interp1d
      4 
----> 5 x=var
      6 x1 = ([0.1,0.3,0.4])
      7 y1 = [0.2,0.5,0.6]

NameError: name 'var' is not defined

In [9]: 

Answer 3

I got the similar issue.

My error was I named a variable and function name as same.

I corrected that and error vanished.

Answer 4

Int's don't have a min() function but min() is a builtin function. You'll need to use min(x).

Answer 5

Change that line to:

new_x = np.linspace(min(x), max(x), new_length)

min and max are not attributes of lists, they are their own functions.

Answer 6

I encountered a similar error when I called timezone.now instead of timezone.now(). I then tried to format the DateTime value that I was expecting. But it wasn't a DateTime; it was a function. This resulted in an error message about 'Month' not being an attribute of 'function'.

The fix was to simply add the parentheses after now. This called the now function and returned its result, instead of returning the now function object itself.

Silly mistake, I know. But not easy to troubleshoot.