How to locate column and index of an element in a list with different data types

Question

I'm trying to locate the column and index of each element in the 2D list, however I seem unable to do so. The 2D Array is the one below.

Top_Level_Data = [['Fund Code', 'Total Return ( Local )', 'Currency Return', 'Income Return', 'Total Return', 'Contrib. To Return', 'Bmark Total Return'], ['L09CBD', 1.99230092282758, 2.82574117438372e-06,
    0.215178694163583, 1.99230092282758, 1.99230380178837, 2.18128409041032]]

I am for example trying to get the following: Top_Level_Data.index('Fund Code')

However I am receiving errors such as 'Fund Code' is not in list. Could it be because the array contains different data types? Any help would be super appreciated. Thanks!

`column and index of each element in the 2D list`? What do you mean `each`, can you elaborate? — yatu, Sep 03 '19 at 11:10
https://stackoverflow.com/questions/5775352/python-return-2-ints-for-index-in-2d-lists-given-item — SM Abu Taher Asif, Sep 03 '19 at 11:11
Python doesn't do 2D lists. It does lists of lists. You're trying to locate `'Fund Code'` in a list, where every item is a list. — tituszban, Sep 03 '19 at 11:11
Answer - https://stackoverflow.com/questions/17385419/find-indices-of-a-value-in-2d-matrix — AnswerSeeker, Sep 03 '19 at 11:16

Grzegorz Skibinski · Accepted Answer · 2019-09-03T11:46:09.387

1

Try with numpy

>>> import numpy as np
>>> np.where(np.array(Top_Level_Data) == "Currency Return")
(array([0], dtype=int64), array([2], dtype=int64))

And flattened:

>>> np.array(np.where(np.array(Top_Level_Data) == "Currency Return")).ravel()
array([0, 2], dtype=int64)
>>> np.array(np.where(np.array(Top_Level_Data) == "Currency Return")).ravel()[0]
0
>>> np.array(np.where(np.array(Top_Level_Data) == "Currency Return")).ravel()[1]
2

edited Sep 03 '19 at 11:46

answered Sep 03 '19 at 11:14

Grzegorz Skibinski

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Thanks for this. Is there a way to store for example the Index number or the column number as a variable? – GCoxxx Sep 03 '19 at 11:41
yup, you can flatten it using ```ravel()``` - I added paragraph to my answer – Grzegorz Skibinski Sep 03 '19 at 11:46

DjaouadNM · Answer 2 · 2019-09-03T11:39:06.913

It depends on what you want, in all cases, you can use a generator expression and use next to get the first element generated:

If you want the index of the sublist that contains `'Fund Code'`:

try:
    res = next(i for i, v in enumerate(Top_Level_Data) if 'Fund Code' in v)
except StopIteration:
    res = -1
# output: 0

If you want the index of `'Fund Code'` in the sublist that contains it:

try:
    res = next(v.index('Fund Code') for v in Top_Level_Data if 'Fund Code' in v)
except StopIteration:
    res = -1
# output: 0

If you want both:

try:
    res = next((i, v.index('Fund Code')) for i, v in enumerate(Top_Level_Data) if 'Fund Code' in v)
except StopIteration:
    res = (-1, -1)
# output: (0, 0)

`next(i for i, v in enumerate(Top_Level_Data) if 'Fund Code' in v)` raises `StopIteration` if the key is not present. +1 nevertheless — gboffi, Sep 03 '19 at 11:35

How to locate column and index of an element in a list with different data types

2 Answers2

If you want the index of the sublist that contains 'Fund Code':

If you want the index of 'Fund Code' in the sublist that contains it:

If you want both:

If you want the index of the sublist that contains `'Fund Code'`:

If you want the index of `'Fund Code'` in the sublist that contains it: