Return copy of dictionary excluding specified keys
I want to make a function that returns a copy of a dictionary excluding keys specified in a list.
Considering this dictionary:
my_dict = {
"keyA": 1,
"keyB": 2,
"keyC": 3
}
A call to without_keys(my_dict, ['keyB', 'keyC'])
should return:
{
"keyA": 1
}
I would like to do this in a one-line with a neat dictionary comprehension but I'm having trouble. My attempt is this:
def without_keys(d, keys):
return {k: d[f] if k not in keys for f in d}
which is invalid syntax. How can I do this?
You were close, try the snippet below:
>>> my_dict = {
... "keyA": 1,
... "keyB": 2,
... "keyC": 3
... }
>>> invalid = {"keyA", "keyB"}
>>> def without_keys(d, keys):
... return {x: d[x] for x in d if x not in keys}
>>> without_keys(my_dict, invalid)
{'keyC': 3}
Basically, the if k not in keys
will go at the end of the dict comprehension in the above case.
In your dictionary comprehension you should be iterating over your dictionary (not k
, not sure what that is either). Example -
return {k:v for k,v in d.items() if k not in keys}
This should work for you.
def without_keys(d, keys):
return {k: v for k, v in d.items() if k not in keys}
Even shorter. Apparently python 3 lets you 'subtract' a list
from a dict_keys
.
def without_keys(d, keys):
return {k: d[k] for k in d.keys() - keys}