Python | Remove prefix strings from list

Sometimes, while working with data, we can have a problem in which we need to filter the strings list in such a way that strings starting with specific prefix are removed. Let’s discuss certain ways in which this task can be performed.

Method #1 : Using loop + remove() + startswith() The combination of above functions can solve this problem. In this, we remove the elements that start with particular prefix accessed using loop and return the modified list. 

Python3

# Python3 code to demonstrate working of
# Remove prefix strings from list
# using loop + remove() + startswith()

# initialize list
test_list = ['xall', 'xlove', 'gfg', 'xit', 'is', 'best']

# printing original list
print("The original list : " + str(test_list))

# initialize prefix
pref = 'x'

# Remove prefix strings from list
# using loop + remove() + startswith()
for word in test_list[:]:
    if word.startswith(pref):
        test_list.remove(word)

# printing result
print("List after removal of Kth character of each string : " + str(test_list))

Output : 

The original list : ['xall', 'xlove', 'gfg', 'xit', 'is', 'best']
List after removal of Kth character of each string : ['gfg', 'is', 'best']

Method #2 : Using list comprehension + startswith() This is another way in which this task can be performed. In this, we don’t perform removal in place, instead, we recreate the list without the elements that match the prefix. 

Python3

# Python3 code to demonstrate working of
# Remove prefix strings from list
# using list comprehension + startswith()

# initialize list
test_list = ['xall', 'xlove', 'gfg', 'xit', 'is', 'best']

# printing original list
print("The original list : " + str(test_list))

# initialize prefix
pref = 'x'

# Remove prefix strings from list
# using list comprehension + startswith()
res = [ele for ele in test_list if not ele.startswith(pref)]

# printing result
print("List after removal of Kth character of each string : " + str(res))

Output : 

The original list : ['xall', 'xlove', 'gfg', 'xit', 'is', 'best']
List after removal of Kth character of each string : ['gfg', 'is', 'best']

Method#3: Using filter() + startswith() This is another way in which this task can be performed. In this, we create new list by using filter function from the old list. Filter function filter out string which starts with defined prefix.

Python3

# Python3 code to demonstrate working of
# Remove prefix strings from list
# using filter + startswith()

# initialize prefix
pref = 'x'

def eva(x):
    return not x.startswith(pref)
# initialize list
test_list = ['xall', 'xlove', 'gfg', 'xit', 'is', 'best']

# printing original list
print("The original list : " + str(test_list))

# Remove prefix strings from list
# using filter + startswith()
res = list(filter(eva, test_list))

# printing result
print("List after removal of Kth character of each string : " + str(res))

Output:

The original list : ['xall', 'xlove', 'gfg', 'xit', 'is', 'best']
List after removal of Kth character of each string : ['gfg', 'is', 'best']

Method #4: Without using startswith() method

Python3

# Python3 code to demonstrate working of
# Suffix removal from String list

# initialize list
test_list = ['xall', 'xlove', 'gfg', 'xit', 'is', 'best']

# printing original list
print("The original list : " + str(test_list))

# initialize suffix
pref = "x"

res=[]
# Suffix removal from String list
for i in test_list:
    if(i[0]!=pref):
        res.append(i)

# printing result
print("List after removal of suffix elements : " + str(res))

Output

The original list : ['xall', 'xlove', 'gfg', 'xit', 'is', 'best']
List after removal of suffix elements : ['gfg', 'is', 'best']