Removing values >0 in data set
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I have a data set which is a list of lists, looking like this:
[[-0.519418066, -0.680905835], [0.895518429, -0.654813183], [0.092350219, 0.135117023], [-0.299403315, -0.568458405],....]
its shape is (9760,) and I am trying to remove all entries where the value of the first number in each entry is greater than 0, so in this example the 2nd and 3rd entries would be removed to leave
[[-0.519418066, -0.680905835], [-0.299403315, -0.568458405],....]
So far I have written:
for x in range(9670): for j in filterfinal[j]: if filterfinal[j] > 0: np.delete(filterfinal[j])
this returns: TypeError: list indices must be integers or slices, not list
Thanks in advance for any help on this problem!
You can use
numpy's boolean indexing:
>>> x = np.random.randn(10).reshape((5,2)) array([[-0.46490993, 0.09064271], [ 1.01982349, -0.46011639], [-0.40474591, -1.91849573], [-0.69098115, 0.19680831], [ 2.00139248, -1.94348869]]) >>> x[x[:,0] > 0] array([[ 1.01982349, -0.46011639], [ 2.00139248, -1.94348869]])
x[:,0] selects the first column of your array.
x > 0 will return an array of the same shape where each value is replaced by the result of the element-wise comparison (i.e., is the value > 0 or not?)
x[:,0] > 0 will give you an array of shape
False values depending on the first value of your row.
You can then pass this array of booleans as an index to your original array, where it will return you an array of only the indexes that are
True. By passing in a boolean array of shape
(n,1), you select per row.
array = np.array([[-0.519418066, -0.680905835], [0.895518429, -0.654813183], [0.092350219, 0.135117023], [-0.299403315, -0.568458405]]) filtered = array[array[:, 0] < 0]
Python List remove(), Return Value from remove(). The remove() doesn't return any value (returns None ). Example 1: Remove element from the list. From the left pane in Registry Editor, drill down until you locate the registry key that you want to delete or the key that contains the registry value you want to remove. You can not delete registry hives, the top-level keys you see in Registry Editor. Once found, right-click or tap-and-hold on it and choose Delete.
Use a list comprehension:
lol = [[-0.519418066, -0.680905835],[0.895518429, -0.654813183],[0.092350219, 0.135117023],[-0.299403315, -0.568458405]] filtered_lol = [l for l in lol if l <= 0]
SQL DELETE Statement, Exercise: Delete all the records from the Customers table where the Country value is 'Norway'. Customers Country =� If we want to remove multiple values from a vector, we can use the %in% operator. Have a look at the following R code: vec_new <- vec [! vec % in % c ("A", "C")] # Remove multiple values vec_new # Print updated vector # "B" "D" As you can see based on the output of the RStudio console, we deleted every “A” and every “C” from our vector.
You can use a list comprehension that unpacks the first item from each sub-list and retains only those with the first item <= 0 (assuming your list of lists is stored as variable
[l for a, _ in l if a <= 0]
6.5 Removing Values, 6.5 Removing Values. As well as assigning values for parameters, you will sometimes want to remove parameter values from editors. For example:. Go to the Data tab and select the Filter command. Use the keyboard shortcut Ctrl + Shift + L.
You can go through this in a for loop and making a new list without the positives like so:
new_list =  for item in old_list: if item < 0: new_list.append(item)
But I'd prefer to instead use the in built
filter function if you are comfortable with it and do something like:
def is_negative(number): return number < 0 filtered_list = filter(is_negative, old_list)
This is similar to a list comprehension - or just using a for loop. However it returns a generator instead so you never have to hold two lists in memory making the code more efficient.
Is there a simple way to delete a list element by value?, To remove an element's first occurrence in a list, simply use list.remove : >>> a = [ 'a', 'b', 'c', 'd'] >>> a.remove('b') >>> print(a) ['a', 'c', 'd']. Mind that it does not� The simplest way to fix it would be an IF based formula, however replacing all the cells containing a space with empty cells would remove the #VALUE. Select Replace from the Find & Select button on the Home tab. In the Find what box type a space. Click the Options button and check Match entire cell contents.
What ways can we use to remove elements from a list in Python , One other method from removing elements from a list is to take a slice of the list, which excludes the index or indexes of the item or items you are trying to� Remove duplicate values Select the range of cells that has duplicate values you want to remove. Tip: Remove any outlines or subtotals from your Click Data > Remove Duplicates, and then Under Columns, check or uncheck the columns where you want to remove the Click OK.
Removing values from a variable. - MATLAB Answers, How can I remove the value of 4 5 6 and 5 5 6 in A, based on B's second and third column? My resultant, should be [1 2 2; 2 2 2; 3 1 2; 7 1 2]. 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 multiple elements from a list in Python, Given a list of numbers, write a Python program to remove multiple elements from a list based on the given condition. Example: Input: [12, 15, 3, 10] Output:� Python list method remove() searches for the given element in the list and removes the first matching element. Syntax. Following is the syntax for remove() method − list.remove(obj) Parameters. obj − This is the object to be removed from the list. Return Value. This Python list method does not return any value but removes the given object from the list.
- what have you tried - the simple way to start is using for loops, nothing wrong with that. Also StackOverflow is not supposed to be a place to get code written for you - it's somewhere you bring code you wrote that doesn't work and ask for help fixing it.
- sorry I havent been using stack overflow for very long I will edit with the code I have written