从字典列表中删除键值对

Question

I have a list of dictionaries such as:

[{'mykey1':'myvalue1', 'mykey2':'myvalue2'}, {'mykey1':'myvalue1a', 'mykey2':'myvalue2a'}]

I need to remove all key values pairs from all dictionaries where the key is equal to mykey1. I could do this by looping through and using the del statement, but I am wondering how I would create a new list using list comprehensions or lambdas which would just remove all key value pairs where the key was mykey1.

Many thanks

Answer 1

I have a list of dictionaries such as:

[{'mykey1':'myvalue1', 'mykey2':'myvalue2'}, {'mykey1':'myvalue1a', 'mykey2':'myvalue2a'}]

I need to remove all key values pairs from all dictionaries where the key is equal to mykey1. I could do this by looping through and using the del statement, but I am wondering how I would create a new list using list comprehensions or lambdas which would just remove all key value pairs where the key was mykey1.

Many thanks

Answer 2

I have a list of dictionaries such as:

[{'mykey1':'myvalue1', 'mykey2':'myvalue2'}, {'mykey1':'myvalue1a', 'mykey2':'myvalue2a'}]

I need to remove all key values pairs from all dictionaries where the key is equal to mykey1. I could do this by looping through and using the del statement, but I am wondering how I would create a new list using list comprehensions or lambdas which would just remove all key value pairs where the key was mykey1.

Many thanks

Answer 3

I have a list of dictionaries such as:

[{'mykey1':'myvalue1', 'mykey2':'myvalue2'}, {'mykey1':'myvalue1a', 'mykey2':'myvalue2a'}]

I need to remove all key values pairs from all dictionaries where the key is equal to mykey1. I could do this by looping through and using the del statement, but I am wondering how I would create a new list using list comprehensions or lambdas which would just remove all key value pairs where the key was mykey1.

Many thanks

Answer 4

I have a list of dictionaries such as:

[{'mykey1':'myvalue1', 'mykey2':'myvalue2'}, {'mykey1':'myvalue1a', 'mykey2':'myvalue2a'}]

I need to remove all key values pairs from all dictionaries where the key is equal to mykey1. I could do this by looping through and using the del statement, but I am wondering how I would create a new list using list comprehensions or lambdas which would just remove all key value pairs where the key was mykey1.

Many thanks

Answer 5

I have a list of dictionaries such as:

[{'mykey1':'myvalue1', 'mykey2':'myvalue2'}, {'mykey1':'myvalue1a', 'mykey2':'myvalue2a'}]

I need to remove all key values pairs from all dictionaries where the key is equal to mykey1. I could do this by looping through and using the del statement, but I am wondering how I would create a new list using list comprehensions or lambdas which would just remove all key value pairs where the key was mykey1.

Many thanks

Answer 6

It's nice to have a one liner list comprehensions but the performance might not be as good as del operation. See my test results below:

%%timeit
dl = [
    {"foo": 1, "bar": 2},
    {"foo": 1, "bar": 2},
    {"foo": 1, "bar": 2},
    {"foo": 1, "bar": 2},
    {"foo": 1, "bar": 2},
    {"foo": 1, "bar": 2},
    {"foo": 1, "bar": 2},
    {"foo": 1, "bar": 2}
]
dl1 = [{key: value for key, value in d.items() if key != 'foo'} for d in dl]

2.78 µs ± 62.7 ns per loop (mean ± std. dev. of 7 runs, 100,000 loops each)

%%timeit
dl = [
    {"foo": 1, "bar": 2},
    {"foo": 1, "bar": 2},
    {"foo": 1, "bar": 2},
    {"foo": 1, "bar": 2},
    {"foo": 1, "bar": 2},
    {"foo": 1, "bar": 2},
    {"foo": 1, "bar": 2},
    {"foo": 1, "bar": 2}
]
for row in dl:
    del row['foo']

640 ns ± 13.7 ns per loop (mean ± std. dev. of 7 runs, 1,000,000 loops each)