How to convert a list of tuples of floats to list of strings in Python?

Question

I have a list of tuples as follows -

my_list = [(0, nan), (20.307, 0.14045), (-16.879, 0.09363), (4.598, 0.06323)]

This list is a result of -

my_list = list(zip(list_a,list_b))

where list_b was created by appending the variances calculated from a series, hence the nan .

The expected output is -

my_list = ['0, nan','20.307, 0.14045', '-16.879, 0.09363', '4.598, 0.06323']

I tried looping through my_list but I am getting the error - NameError: name 'nan' is not defined

Please guide. Thanks

Answer 1

float("nan") is how python represents NaN .

you could do just this:

my_list = [(0, float("nan")), (20.307, 0.14045), (-16.879, 0.09363), (4.598, 0.06323)]

ret = [', '.join(str(i) for i in items) for items in my_list]
# ['0, nan', '20.307, 0.14045', '-16.879, 0.09363', '4.598, 0.06323']

or if there are always just two items in your list you could use an f-string:

ret = [f'{a}, {b}' for a, b in my_list]

Answer 2

my_list = [(0, None), (20.307, 0.14045), (-16.879, 0.09363), (4.598, 0.06323)]

result = [f'{x[0]},{x[1]}' for x in my_list]

you can do it with this for each tuple in list add a string that consist first item and second item

Answer 3

Your question is somewhat unclear, but let me answer to the best of my abilities. In any case, first thing you may need to do is:

from math import nan

to allow usage of nan literal. If you want to convert my_list to strings, there is a oneliner that can do it:

my_list_strings = [", ".join(map(str, one_tuple)) for one_tuple in my_list]

Or, did you want my_list to be list of strings in the first place? One way to achieve that:

my_list = []
for single_str in zip(list_a, list_b):
    my_list.append(str(single_str[0]) + ", " + str(single_str[1]))