如何根据条件根据另一个相同长度的嵌套列表将列表中的项目替换为空字符串

Question

I have a header list as below:

h_list = ['h1','h2','h3','h4','h5']

Now I have data list (Nested):

d_list = [
[1, None, 3, ' ', 5],
[1, ' ', 2, ' ', 9]
]

Both lists are of same length every time, so I want to match in each list of nested list at same index position and if its all corresponding values are either None or ' ' , then replace the item from h_list to ' ' (Empty string)

My expected output is:

h_list = ['h1',' ','h3',' ','h5']

Answer 1

Try a list comprehension:

h_list = ['h1','h2','h3','h4','h5']


d_list = [
[1, None, 3, ' ', 5],
[1, ' ', 2, ' ', 9]
]

empty = [' ', None]
h_list = [' ' if any(b[i] in empty for b in d_list) else v for i, v in enumerate(h_list)]
print(h_list)

Output:

['h1', ' ', 'h3', ' ', 'h5']

---

Breaking down this part of the code:

h_list = [' ' if any(b[i] in empty for b in d_list) else v for i, v in enumerate(h_list)]

First, lets have only

[(i, v) for i, v in enumerate(h_list)]

The above will be a list of the indices and values of each element in h_list .

Now, we use an if statement to determine when to add the ' ' . First, we need to recognize the any() function:

any(b[i] in empty for b in d_list)

returns True if any of the arrays inside d_list at index i is in the empty list. We want None and ' ' to be in place for all the strings in h_list that its index returns a ' ' or None for any of the lists in d_list , so:

[' ' for i, v in enumerate(h_list) if any(b[i] in empty for b in d_list)]

Finally, we want to use the original string if not any(b[i] in empty for b in d_list) . For that, we use an else statement (note that with an else , the statements get shifted to the left side of the for loop.) :

h_list = [' ' if any(b[i] in empty for b in d_list) else v for i, v in enumerate(h_list)]

Answer 2

I believe this should work for your examples:

new_list = []
for orig_element, *values in zip(h_list, *d_list):
    new_list.append(orig_element if any(not (v is None or str(v).strip() == '') for v in values) else '')

If you want to modify the list in-place simply do:

for i, (orig_element, *values) in enumerate(h_list, *d_list):
    h_list[i] = orig_element if any(not (v is None or str(v).strip() == '') for v in values) else ''

Answer 3

Basic solution

h_list = ['h1','h2','h3','h4','h5']
d_list = [
[1, None, 3, ' ', 5],
[1, ' ', 2, ' ', 9]
]
# loop over d_list
for i in d_list:
# loop over inner list 
    for k in i:
# if type not int, give me space in that index
        if type(k)!=int:
            h_list[i.index(k)]=" "
h_list

Answer 4

You can use zip with all :

h_list = ['h1','h2','h3','h4','h5']
d_list = [[1, None, 3, ' ', 5], [1, ' ', 2, ' ', 9]]
r = [' ' if all(k in {None, ' '} for k in j) else a for a, j in zip(h_list, zip(*d_list))]

Output:

['h1', ' ', 'h3', ' ', 'h5']