Lists

Question 1

last 10 elements in list el_list

Answer 1

el_list[-10:]

Question 2

Get index and value of maximum element in the list l1

Answer 2

1)import operator
index, value = max(enumerate(l1), key=operator.itemgetter(1))

2)max_value = max(my_list)
max_index = my_list.index(max_value)

2*)max_index = my_list.index(max(my_list))

Question 3

create List of nonzero elements of list a

2 ways

Answer 3

1) nonzeroind =[i for i, e in enumerate(a) if e != 0]

2) nonzeroind = np.nonzero(a)[0]

Question 4

find categorical columns after defining numerical columns

Answer 4

numeric_cols = ['RFCD.Percentage.1', 'RFCD.Percentage.2']
categorical_cols = list(set(X.columns.values.tolist()) - set(numeric_cols))

Question 5

Count number of unique elements in list

Answer 5

from collections import Counter

orig = [‘a’, ‘b’, ‘a’, ‘c’, ‘b’, ‘a’, ‘c’]

res = Counter(orig)

Question 6

1) Make numpy array from list_l1

2) Make list from numpy array np_l1

Answer 6

1) np_l1 = numpy.array(list_l1)

2) list_l1 = list(np_l1)

Question 7

Reverse list

Answer 7

brr[:] = brr[::-1]