Removing values from an 2d array-CodePudding

I have a 2 dimensional numpy array and want to remove all 'false' values. A nested array with different lengths should be created.

[['false' 'value1' 'false' 'false' 'value5' 'false' 'false' 'false'
  'false' 'false' 'false' 'false' 'false' 'false' 'false' 'false']
 ['false' 'value1' 'false' 'false' 'false' 'false' 'false' 'false'
  'false' 'value10' 'value11' 'false' 'false' 'false' 'false'
  'false']]

I would like to get:

[['value1' 'value5']
 ['value1' 'value10' 'value11']]

CodePudding user response：

You should make use of the filter() built-in-function

>>> an_array = ['false', 'a', 'b', 'c', 'false']
>>> filtered_array = list(filter(lambda a: a != 'false', an_array))
['a', 'b', 'c']

CodePudding user response：

you cant have different lengths in a numpy array but you can make it into a 2d array and then just sort the values like this:

arr = [['false', 'value1', 'false', 'false', 'value5', 'false', 'false', 'false',
        'false', 'false', 'false', 'false', 'false', 'false', 'false', 'false'],
        ['false', 'value1', 'false', 'false', 'false', 'false', 'false', 'false',
        'false', 'value10', 'value11', 'false', 'false', 'false', 'false',
        'false']]
List1 = []
List2 = []
for x in arr:
    for char in x:
        if char != "false" and x == arr[0]:
            List1.append(char)
        elif char != "false" and x == arr[1]:
            List2.append(char)
print(List1)
print(List2)

and then you get 2 lists that dont contain the false values.

CodePudding user response：

You need to iterated for each list in your lists and then apply the filter function and append a new list with this output

lists = [['false', 'value1', 'false', 'false', 'value5', 'false', 'false', 'false', 'false', 'false', 'false', 'false', 'false', 'false', 'false', 'false'],
 ['false', 'value1', 'false', 'false', 'false', 'false', 'false', 'false', 'false', 'value10', 'value11', 'false', 'false', 'false', 'false', 'false']]
filtered_list = []

for x in lists:
    filtered_list.append(list(filter(lambda a: a!="false", x)))

filtered_list

in the filtered_list var you will get the output