How can I delete a specific element of a list in a combined list of lists?

python remove multiple elements from list by index
remove element from list of lists python
remove element from list python
python remove list from list
python list
remove multiple characters from list python
python delete specific elements from list
remove range of elements from list python

I am trying to find a way to check a list which contains several other lists for a specific element and delete it.

So basically I have 2 lists (a and b) which are combined in another list (c)

a= ["aa","bb"]
b= ["aa","dd"]
c=[a,b]

Now I am trying to delete all elements named "aa"

c.remove("aa")

Sadly this doesn't work and I get the error "ValueError: list.remove(x): x not in list" because "aa" is not literally mentioned in c.

In the end I also want to print out all the lists in c and what they contain. Something like that:

c= a: bb, b: dd
  • Is there a way to delete elements in several lists with a single command like I tried with combining them in another list c?

  • And how can I print out the list c in the end similar to how I described it above?

You can use a list comprehension:

a = ['aa', 'bb']
b = ['aa', 'dd']
c = [a, b]

c = [[x for x in sublist if x != 'aa'] for sublist in c]

This solution will remove all 'aa' elements, while list.remove('aa') in a regular for loop will only remove the first occurrence in each sublist.

Remove an item from a list in Python (clear, pop, remove, del), What built in list method would you use to remove items from a list? Remove multiple elements from list while Iterating Iterate over the list and remove them one by one if its divisible by 3 i.e.

You'll need to iterate through the individual lists in list c. For example

>>> a = ["aa", "bb"]
>>> b = ["aa", "dd"]
>>> c = [a, b]
>>> for i in c:
...   i.remove("aa")
... 
>>> c
[['bb'], ['dd']]
>>> 

Python : How to remove multiple elements from list ? – thispointer.com, How do you remove multiple items from a list in Python? You can easily edit, delete, or restore recently deleted list elements such as accounts, terms, classes, products, or services. Edit a list element. You can easily edit a list element: Select Settings ⚙️. Under Lists, choose All Lists. Open the appropriate list, for example, Chart of Accounts, Products and Services, etc. Select Edit in the

Your desired output looks like a dictionary. You can create this using a dict comprehension, as such:

a= ["aa","bb"]
b= ["aa","dd"]
mylist_names = ['a','b']
c={name:[x for x in vals if x!='aa'] for name, vals in zip(mylist_names, [a,b])}

>>> c
{'a': ['bb'], 'b': ['dd']}

How do I remove an element from a list by index in Python?, How do you remove all occurrences of an element from a list in Python? When the list is empty, what value will the pointer to the beginning have? Answer: There are no nodes to point to, so it will be NULL! Different cases: There are a few steps to deleting a specific element from the list: Find the node with the element (if it exists). Remove that node. Reconnect the linked list.

If you don't mind using numpy

import numpy as np

a= ["aa","bb",'cc']
b= ["aa","dd", 'kk']
c= np.asarray([a,b])

to_remove = ['aa']

c = [x[~np.isin(x,to_remove)].tolist() for x in c]

output = [['bb', 'cc'], ['dd', 'kk']]

Should work for everything you need including multiple items you want to get rid of.

import numpy as np

a= ["aa","bb",'cc']
b= ["aa","dd", 'kk']
c= np.asarray([a,b])

to_remove = ['aa', 'kk']

c = [x[~np.isin(x,to_remove)].tolist() for x in c]

output = [['bb', 'cc'], ['dd']]

Python, How do I remove a specific index from a list in Python? In Python, list's methods clear(), pop(), and remove() are used to remove items (elements) from a list. It is also possible to delete items using del statement by specifying a position or range with an index or slice. Remove all items: clear() Remove an item by index and get its value: pop() Remove an item by value: remove()

Remove Elements From Lists | Python List remove() Method, The problem of removing a row from a list is quite simple and we just need to pop a we need to delete a column i.e particular index element of each of the list. Remove an element from List by Index using list.pop () Python. list.pop (index) 1. list.pop(index) In python list’s pop () function will remove the element at given index and also returns the deleted element. If index is not given then it deletes the last element.

11. Lists, A single list may contain data types like strings, integers, floating point numbers etc. Lists support indexing and slicing, just like strings. Lists are  Removes from the container all the elements that compare equal to val. This calls the destructor of these objects and reduces the container size by the number of elements removed. Unlike member function list::erase , which erases elements by their position (using an iterator), this function ( list::remove ) removes elements by their value.

Java Generics and Collections, Remove Multiple elements from list by index range using del. Suppose we want to remove multiple elements from a list by index range, then we can use del keyword i.e. It will delete the elements in list from index1 to index2 – 1. How to insert elements in C++ STL List ? This article covers the deletion aspects in STL list. Using list::erase(): The purpose of this function is to remove the elements from list. Single or multiple contiguous elements in range can be removed using this function. This function takes 2 arguments, start iterator and end iterator.

Comments
  • For each sublist L you want to create f(L) where f is "remove all aa elements". Then you create a list of returned f-s of sublists: res = [f(a), f(b)]. This is what map for: book.pythontips.com/en/latest/map_filter.html#map .
  • filter might be helpful if you make a lambda.
  • Thanks a lot! This is probably the easiest way :)
  • But can you maybe explain to me in a bit more detail how the last line of your code works?
  • @NewHere, For each outer list comprehension, i.e. for sublist in c, the inner list comprehension, [x for x in ...], constructs a list. The result is a list of lists.
  • Thank you for the explenation :)