Concatenate strings in nested list based on index

Question

I am trying to concatenate strings based on the similar values in them (on different indices). At the moment, the snippet works fine for a maximum of three words in consecutive order, but breaks for four.

For example:

reg = [
        ['Abraham', 0.9, 1.6],
        ['King', 1.6, 2.4],
        ['Late', 2.4, 3.2],
        ['Moto', 11.3, 11.9],
        ['GP', 11.9, 12.7],
        ['Ferrari', 14.7, 15.1],
        ['GT-86', 15.1, 15.8],
        ['HP', 16.1, 16.6],
        ['Envy', 16.6, 17.0],
        ['16', 17.0, 17.4],
        ['DV', 17.4, 18.0]
    ]


temp_word = ''
result_lst = []
isBool = False

for indx, elem in enumerate(reg):
    try:
        if elem[2] == reg[indx+1][1]:
            if isBool:
                temp_word += elem[0] + reg[indx+1][0]
                result_lst.append(temp_word)
            else:
                temp_word = elem[0]
                isBool = not isBool
        else:
            temp_word = ''
    except IndexError:
        pass

print(result_lst)
#Output:

#['AbrahamKingLate', 'MotoGP', 'FerrariGT-86', 'HPEnvy', 'HPEnvyEnvy16', 'HPEnvyEnvy1616DV']   


# Desired: 
# ['AbrahamKingLate', 'MotoGP', 'FerrariGT-86', 'HPEnvy16DV']

Any help would be very much appreciated!

ekhumoro · Accepted Answer · 2020-02-25 10:18:09Z

1

This can be done quite simply by saving the previous item and then comparing it to the current item, like this:

result = []
previous = None
for current in reg:
    if previous and current[1] == previous[2]:
        result[-1] += current[0]
    else:
        result.append(current[0])
    previous = current

print(result)

Output:

['AbrahamKingLate', 'MotoGP', 'FerrariGT-86', 'HPEnvy16DV']

answered Feb 25, 2020 at 10:18

ekhumoro

122k23 gold badges272 silver badges400 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

zipa · Accepted Answer · 2020-02-25 09:49:26Z

0

This will do it:

result = [reg[0]]

for item in reg[1:]:
    r_num = result[-1][2]
    r_name = result[-1][0]
    i_num = item[1]
    i_name = item[0]
    if i_num == r_num:
        result[-1] = [r_name+i_name] + item[1:]
    else:
        result.append(item)

result = [r[0] for r in result]

result
# ['AbrahamKingLate', 'MotoGP', 'FerrariGT-86', 'HPEnvy16DV']

answered Feb 25, 2020 at 9:49

zipa

28k6 gold badges45 silver badges62 bronze badges

Comments

Sayandip Dutta · Accepted Answer · 2020-02-25 09:58:39Z

0

Try this:

names = []
first_elem = reg[0][0]

for ix, l in enumerate(reg[1:]):
    if l[1] == reg[ix][-1]:
        first_elem = first_elem + l[0]
    else:
        names.append(first_elem)
        first_elem = l[0]
names.append(first_elem)
print(names)

# ['AbrahamKingLate', 'MotoGP', 'FerrariGT-86', 'HPEnvy16DV']

answered Feb 25, 2020 at 9:58

Sayandip Dutta

15.9k4 gold badges27 silver badges57 bronze badges

Collectives™ on Stack Overflow

Concatenate strings in nested list based on index

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related