Filter ()() Function in Python

This guide covers filter ()() function in python with practical context and easy-to-follow details. Use it to understand the subject and apply the information confidently.

filter(func, iterable)

The filter () function has 2 parameters:

• Func: Is a conditional function to check whether the elements in Interable Are true or false, Func Can only return True or False.
• Interable: Is iterable to filter, can be set, list, tuple or container.

# danh sách ch? cái
alphabet = ['a', 'b', 'd', 'e', 'i', 'j', 'o']

# l?c nguyên âm
# vi?t b?i TipsMake.com
def filterNguyenam(alphabet):
 nguyenam = ['a', 'e', 'i', 'o', 'u']

if(alphabet in nguyenam):
 return True
 else:
 return False

filterNguyenam = filter(filterNguyenam, alphabet)

print('Các nguyên âm ???c l?c là:')
for nguyenam in filterNguyenam:
 print(nguyenam)

Run the program, the result is:

Các nguyên âm ???c l?c là:
a
e
i
o

Here, we list a list of letters and need to filter out vowels in it.

You can use a for loop to test each component in the list and store it to another list, but using Python the process will be easier and faster by using the filter method (). .

# random list
# vi?t b?i TipsMake.com
randomList = [1, 'a', 0, False, True, '0']

filteredList = filter(None, randomList)

print('Các ph?n t? ???c l?c là:')
for element in filteredList:
 print(element)

Run the program, the result is:

Các ph?n t? ???c l?c là:
1
a
True
0

Here, we have a random list of numbers, strings and boolean called randomList. We pass randomList to the filter () function with the first parameter (func) being None. At this point, the function itself becomes Identity function by default, so we get TRUE elements 1, a, True and '0' ('0' in string form).

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