Stacking lists into arrays in python2.7

Question

I'm trying to work out how to add multiple lists to an array. Following is what I've come up with but it's not working.

import math
import numpy as np

myList1 = [1,2,'nan']
myList2 = [3,4,5]

class myThing(object):
    def __init__(self, myLists=[]): #This could accept 1 or many lists
    self.__myVars = np.array(myLists, dtype=float)
    self.__myVars.shape = (len(myLists),3)
    self.__myVars = np.vstack(myVars)

        @property
    def myVars(self):
        return self.__myVars

foo = myThing(myList1,myList2)
print foo.myVars

blah blah...
TypeError: __init__() takes at most 2 arguments (3 given)

Help appreciated

score 0 · Accepted Answer · edited May 23 '17 at 11:57

Use *myLists in def __init__ to allow __init__ to accept an arbitrary number of arguments:

def __init__(self, *myLists): #This could accept 1 or many lists

import numpy as np

myList1 = [1,2,'nan']
myList2 = [3,4,5]

class myThing(object):
    def __init__(self, *myLists): #This could accept 1 or many lists
        self.__myVars = np.array(myLists, dtype=float)

    @property
    def myVars(self):
        return self.__myVars

foo = myThing(myList1,myList2)
print foo.myVars

yields

[[  1.   2.  nan]
 [  3.   4.   5.]]

Also, when debugging errors, it's useful to look at more than the exception itself. The full traceback includes the line on which the Exception occurred:

---> 20 foo = myThing(myList1,myList2)
     21 print foo.myVars

TypeError: __init__() takes at most 2 arguments (3 given)

This can help clue us in to what is causing the problem.

score 0 · Answer 2 · answered Dec 06 '14 at 12:47

0

I think you mean:

def __init__(self, *myLists): #This could accept 1 or many lists

answered Dec 06 '14 at 12:47

xnx

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Stacking lists into arrays in python2.7

2 Answers2