Last updated: Feb 20, 2023
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Use a list comprehension to remove the empty strings from a list of strings.
The list comprehension will return a new list that doesn't contain any empty strings.
my_list = ['bobby', '', 'hadz', '', 'com', ''] new_list = [item for item in my_list if item] print(new_list) # ๐๏ธ ['bobby', 'hadz', 'com']
The example uses a list comprehension to remove the empty strings from a list.
On each iteration, we check if the current item is truthy and return the result.
my_list = ['bobby', '', 'hadz', '', 'com', ''] new_list = [item for item in my_list if item] print(new_list) # ๐๏ธ ['bobby', 'hadz', 'com']
Empty strings are falsy values, so they get filtered out.
The list comprehension creates a new list, it doesn't mutate the original list.
If you want to remove the empty strings from the original list, use list slicing.
my_list = ['bobby', '', 'hadz', '', 'com', ''] my_list[:] = [item for item in my_list if item] print(my_list) # ๐๏ธ ['bobby', 'hadz', 'com']
We used the my_list[:]
syntax to get a slice that represents the entire list,
so we can assign to the variable directly.
my_list[:]
represents the entire list, so when we use it on the left-hand side, we are assigning to the entire list.This approach changes the contents of the original list.
Alternatively, you can use the filter()
function.
This is a three-step process:
filter()
function to filter out the empty strings.list()
class to convert the filter
object to a list.my_list = ['bobby', '', 'hadz', '', 'com', ''] new_list = list(filter(None, my_list)) print(new_list) # ๐๏ธ ['bobby', 'hadz', 'com']
We used the filter()
function to remove the empty strings from a list.
The filter function takes a function and an iterable as arguments and constructs an iterator from the elements of the iterable for which the function returns a truthy value.
None
for the function argument, all falsy elements of the iterable are removed.An empty string is a falsy value, so all empty strings get removed.
The last step is to use the list() class to
convert the filter
object to a list.
Alternatively, you can use a for loop.
This is a three-step process:
for
loop to iterate over a copy of the list.list.remove()
method to remove the empty strings.my_list = ['bobby', '', 'hadz', '', 'com', ''] for item in my_list.copy(): if item == '': my_list.remove(item) print(my_list) # ๐๏ธ ['bobby', 'hadz', 'com']
We used the list.copy()
method to get a copy of the list.
my_list = ['bobby', '', 'hadz', '', 'com', ''] # ๐๏ธ ['bobby', '', 'hadz', '', 'com', ''] print(my_list.copy())
The list.copy method returns a shallow copy of the object on which the method was called.
However, we can iterate over a copy of the list and remove items from the original list.
my_list = ['bobby', '', 'hadz', '', 'com', ''] for item in my_list.copy(): if item == '': my_list.remove(item) print(my_list) # ๐๏ธ ['bobby', 'hadz', 'com']
list.remove()
method to remove the matching elements.The list.remove() method removes the first item from the list whose value is equal to the passed in argument.
The remove()
method mutates the original list and
returns None.
The most important thing to note when removing items from a list in a for
loop
is to use the list.copy()
method to iterate over a copy of the list.
If you try to iterate over the original list and remove items from it, you might run into difficult to locate bugs.
You can also use a list comprehension to remove all empty elements from a list.
# โ Remove empty elements from a list (using list comprehension) my_list = ['a', '', [], (), None, 'b', '', 'c'] new_list = [item for item in my_list if item] print(new_list) # ๐๏ธ ['a', 'b', 'c']
The example uses a list comprehension to remove the falsy values from a list.
my_list = ['a', '', [], (), None, 'b', '', 'c'] new_list = [item for item in my_list if item] print(new_list) # ๐๏ธ ['a', 'b', 'c']
On each iteration, we check if the current item is truthy and return the result.
All values that are not truthy are considered falsy. The falsy values in Python are:
None
and False
.0
(zero) of any numeric type""
(empty string), ()
(empty tuple), []
(empty list), {}
(empty dictionary), set()
(empty set), range(0)
(empty
range).None
, False
, empty string, empty list, empty tuple, etc from the list.The list comprehension creates a new list, it doesn't mutate the original list.
If you want to remove the empty elements from the original list, use list slicing.
my_list = ['a', '', [], (), None, 'b', '', 'c'] my_list[:] = [item for item in my_list if item] print(my_list) # ๐๏ธ ['a', 'b', 'c']
We used the my_list[:]
syntax to get a slice that represents the entire list,
so we can assign to the variable directly.
my_list[:]
represents the entire list, so when we use it on the left-hand side, we are assigning to the entire list.This approach changes the contents of the original list.
Alternatively, you can use the filter()
function.
my_list = ['a', '', [], (), None, 'b', '', 'c'] new_list = list(filter(None, my_list)) print(new_list) # ๐๏ธ ['a', 'b', 'c']
We used the filter()
function to remove the empty elements from a list.
The filter function takes a function and an iterable as arguments and constructs an iterator from the elements of the iterable for which the function returns a truthy value.
None
for the function argument, all falsy elements of the iterable are removed.The last step is to use the list()
class to convert the filter
object to a
list.
Alternatively, you can use a for
loop.
my_list = ['a', '', [], (), None, 'b', '', 'c'] for item in my_list.copy(): if not item: my_list.remove(item) print(my_list) # ๐๏ธ ['a', 'b', 'c']
list.remove()
method to remove the matching elements.The list.remove() method removes the first item from the list whose value is equal to the passed in argument.
The remove()
method mutates the original list and returns None
.
The most important thing to note when removing items from a list in a for
loop
is to use the list.copy()
method to iterate over a copy of the list.
If you try to iterate over the original list and remove items from it, you might run into difficult to locate bugs.
You can learn more about the related topics by checking out the following tutorials: