Fire Brigade - Firemans Drop Key

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Marc Maxmeister's post discusses this but creates an unnecessary (imo) list while doing so. You can simply use a for-loop and throw away the popped values. my_dict = {'a': 1, 'b': 2, 'c': 3, 'd': 4} Now, let’s see what happens when we try to remove a key that doesn’t exist: # Delete a key that doesn't exist using .pop() Now that you have an understanding of how Python dictionary comprehensions work, let’s see how you can use them to delete a key from a dictionary: # Delete a Key using a Dictionary Comprehension

del my_dict[key] is slightly faster than my_dict.pop(key) for removing a key from a dictionary when the key exists >>> import timeit The Drop Key Fireman switch is fitted with a heavy duty DPDT (plunger) double pole micro switch while the Crescent Key Fireman switch is fitted with a heavy duty SPDT (lever) single pole micro switch.You can use a dictionary comprehension to create a new dictionary with that key removed: >>> my_dict = {k: v for k, v in my_dict.items() if k != 'key'}

Now that you have an understanding of what dictionaries are, let’s see how we can use Python to remove a key from a dictionary. Use Python .pop() to Delete a Key from a Dictionary or if you want to use map, then exhaust the map using a deque with max length 0. from collections import deque Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctnessThe auxiliary space required for this code is O(1), as we are only modifying the existing dictionary and not creating any new data structures. Method 2: Remove a Key from a Dictionary using pop() If we want to be able to safelyremove a key from a dictionary, meaning that no error is returned, we can pass in a default value into our .pop()method. A good default value would be to return None, as it allows us to simply move on. # Delete a key that doesn't exist using .pop()

Output: dictionary before performing remove is : {'sai': 22, 'kiran': 21, 'vinod': 21, 'sangam': 21} In the next section, you’ll learn how to remove a key from a Python dictionary using a dictionary comprehension. Use a Python Dictionary Comprehension to Remove a Key from a Dictionary And if you need to catch errors where you pop a value that isn't in the dictionary, use lambda inside map() like this: map(lambda x: myDict.pop(x,None), ['a', 'c', 'e'])Let’s see how we can use the Python dictionary .pop()method to remove a key from our dictionary: # Delete a key using .pop()

W3Schools is optimized for learning and training. Examples might be simplified to improve reading and learning. Using the del keyword; it's almost the same approach like you did though - myDict = {'one': 100, 'two': 200, 'three': 300 }

Auxiliary Space: O(1) Method 3: Using items() + dict comprehension to Remove a Key from a Dictionary The difference between del and pop is that, using pop() method, we can actually store the key's value if needed, like the following: myDict = {'one': 100, 'two': 200, 'three': 300} A drop key and crescent key are required to operate their respective Fireman switch and are available separately. Features Specifically to answer "is there a one line way of doing this?" if 'key' in my_dict: del my_dict['key']