Python | Remove empty tuples from a list

In this article, we will see how can we remove an empty tuple from a given list of tuples. We will find various ways, in which we can perform this task of removing tuples using various methods and ways in Python. 

Examples:

Input : tuples = [(), (‘ram’,’15’,’8′), (), (‘laxman’, ‘sita’), (‘krishna’, ‘akbar’, ’45’), (”,”),()]
Output : [(‘ram’, ’15’, ‘8’), (‘laxman’, ‘sita’), (‘krishna’, ‘akbar’, ’45’), (”, ”)]

Input : tuples = [(”,”,’8′), (), (‘0′, ’00’, ‘000’), (‘birbal’, ”, ’45’), (”), (),  (”,”),()]
Output : [(”, ”, ‘8’), (‘0′, ’00’, ‘000’), (‘birbal’, ”, ’45’), (”, ”)]

Method 1: Using the concept of List Comprehension

Python3

# Python program to remove empty tuples from a
# list of tuples function to remove empty tuples
# using list comprehension
def Remove(tuples):
    tuples = [t for t in tuples if t]
    return tuples

# Driver Code
tuples = [(), ('ram','15','8'), (), ('laxman', 'sita'),
          ('krishna', 'akbar', '45'), ('',''),()]
print(Remove(tuples))

Output

[('ram', '15', '8'), ('laxman', 'sita'), ('krishna', 'akbar', '45'), ('', '')]

Method 2: Using the filter() method

Using the inbuilt method filter() in Python, we can filter out the empty elements by passing the None as the parameter. This method works in both Python 2 and Python 3 and above, but the desired output is only shown in Python 2 because Python 3 returns a generator. filter() is faster than the method of list comprehension. Let’s see what happens when we run the program in Python 2. 

Python

# Python2 program to remove empty tuples
# from a list of tuples function to remove
# empty tuples using filter
def Remove(tuples):
    tuples = filter(None, tuples)
    return tuples

# Driver Code
tuples = [(), ('ram','15','8'), (), ('laxman', 'sita'),
          ('krishna', 'akbar', '45'), ('',''),()]
print Remove(tuples)

Output

[('ram', '15', '8'), ('laxman', 'sita'), ('krishna', 'akbar', '45'), ('', '')]

Now let’s see what happens when we try running the program in Python 3 and above. On running the program in Python 3, as mentioned a generator is returned. 

Python3

# Python program to remove empty tuples from
# a list of tuples function to remove empty
# tuples using filter


def Remove(tuples):
    tuples = filter(None, tuples)
    return tuples


# Driver Code
tuples = [(), ('ram', '15', '8'), (), ('laxman', 'sita'),
          ('krishna', 'akbar', '45'), ('', ''), ()]
print(Remove(tuples))

Output

<filter object at 0x7fae9a596e90>

Method #3 : Using len() method

Python3

# Python program to remove empty tuples from a
# list of tuples function to remove empty tuples
# using len()


def Remove(tuples):
    for i in tuples:
        if(len(i) == 0):
            tuples.remove(i)
    return tuples


# Driver Code
tuples = [(), ('ram', '15', '8'), (), ('laxman', 'sita'),
          ('krishna', 'akbar', '45'), ('', ''), ()]
print(Remove(tuples))

Output

[('ram', '15', '8'), ('laxman', 'sita'), ('krishna', 'akbar', '45'), ('', '')]

Method #4 : Using == operator.Check whether the tuple is equal to empty tuple() and remove if equals.

Python3

# Python program to remove empty tuples from a
# list of tuples function to remove empty tuples
def Remove(tuples):
    for i in tuples:
        if(i==()):
            tuples.remove(i)
    return tuples
# Driver Code
tuples = [(), ('ram','15','8'), (), ('laxman', 'sita'),
        ('krishna', 'akbar', '45'), ('',''),()]
print(Remove(tuples))

Output

[('ram', '15', '8'), ('laxman', 'sita'), ('krishna', 'akbar', '45'), ('', '')]

Method: Using enumerate function

Python3

tuples = [(), ('ram', '15', '8'), (), ('laxman', 'sita'),
          ('krishna', 'akbar', '45'), ('', ''), ()]
res = [t for i, t in enumerate(tuples) if t]
print(res)

Output

[('ram', '15', '8'), ('laxman', 'sita'), ('krishna', 'akbar', '45'), ('', '')]

Time Complexity: O(n)
Auxiliary Space: O(1)

Method: Using while and in operator

Python

# Python program to remove empty tuples from
# a list of tuples function to remove empty
# tuples using while loop and in operator
def Remove(tuples):
    while () in tuples:
        tuples.remove(());
    return tuples

# Driver Code
tuples = [(), ('ram','15','8'), (), ('laxman', 'sita'),
        ('krishna', 'akbar', '45'), ('',''),()]
print (Remove(tuples))

Output

[('ram', '15', '8'), ('laxman', 'sita'), ('krishna', 'akbar', '45'), ('', '')]

Method : Using str(), len() and find() method

Python3

# Python program to remove empty tuples from a
# list of tuples function to remove empty tuples


def Remove(tuples):
    for i in tuples:
        if(str(i).find("()") != -1 and len(str(i)) == 2):
            tuples.remove(i)
    return tuples


# Driver Code
tuples = [(), ('ram', '15', '8'), (), ('laxman', 'sita'),
          ('krishna', 'akbar', '45'), ('', ''), ()]
print(Remove(tuples))

Output

[('ram', '15', '8'), ('laxman', 'sita'), ('krishna', 'akbar', '45'), ('', '')]

Method: Using lambda functions

Python3

# Python program to remove empty tuples from
# a list of tuples function to remove empty
# tuples using lambda function


# Driver Code
tuples = [(), ('ram', '15', '8'), (), ('laxman', 'sita'),
          ('krishna', 'akbar', '45'), ('', ''), ()]

tuples = list(filter(lambda x: len(x) > 0, tuples))
print(tuples)

Output

[('ram', '15', '8'), ('laxman', 'sita'), ('krishna', 'akbar', '45'), ('', '')]

Method : Using  list comprehension , len() method:

Python3

def remove_empty_tuples(tuples):
    return [t for t in tuples if len(t) > 0]

tuples = [(), ('ram','15','8'), (), ('laxman', 'sita'),
          ('krishna', 'akbar', '45'), ('',''),()]
print(remove_empty_tuples(tuples))
#This code is contributed by Edula Vinay Kumar Reddy

Output

[('ram', '15', '8'), ('laxman', 'sita'), ('krishna', 'akbar', '45'), ('', '')]

This method uses a list comprehension to iterate over the list of tuples and check the length of each tuple. If the length is greater than 0, it is included in the new list.

Time complexity: O(n)
Auxiliary Space: O(n)

Method: Using Recursion method 

Python3

#defining recursive function to remove empty tuples in a list
def remove_empty_tuples(start,oldlist,newlist):
  if start==len(oldlist):  #base condition
    return newlist
  if oldlist[start]==():  #checking the element is empty tuple or not
    pass
  else:
    newlist.append(oldlist[start])   #appending non empty tuple element to newlist
  return remove_empty_tuples(start+1,oldlist,newlist)  #recursive function call


tuples = [(), ('ram','15','8'), (), ('laxman', 'sita'),
          ('krishna', 'akbar', '45'), ('',''),()]
#print('The original list: ',tuples)
print(remove_empty_tuples(0,tuples,[]))
#This code is contributed by tvsk

Output

[('ram', '15', '8'), ('laxman', 'sita'), ('krishna', 'akbar', '45'), ('', '')]

Time complexity: O(n)
Auxiliary Space: O(n)