replace a certain value of specific key in list of dictionaries python

user_16343159 0
Viewed 62

I have a list of dictionaries

list1 = [{'time': '2020', 'name': 'one', 'address': '15423'},{'time': '2021', 'name': 'two', 'address': '8548305'}, {'time': '2019', 'name': 'five', 'address': '15423'}]

I want to convert anything that has address with 15423 to 'Valid' and all the other cases Invalid Final output

list1 = [{'time': '2020', 'name': 'one', 'address': 'Valid'},{'time': '2021', 'name': 'two', 'address': 'Invalid'}, {'time': '2019', 'name': 'five', 'address': 'Valid'}]

Here is what I tried

if '15423' in list1['address']:
    list1['address'] = 'Valid'
else:
    list1['address'] = 'Invalid'

But I am not sure why it is not working. Maybe I need to loop through the whole column. Appreciate your help

list dictionary python
3 Answers

You need to iterate over the elements of list1 using a for loop, since list1 is a list of dictionaries:

for i in range(len(list1)):
    if '15423' in list1[i]['address']:
        list1[i]['address'] = 'Valid'
    else:
        list1[i]['address'] = 'Invalid'
        
print(list1)

You can also condense the if/else into a ternary if you're looking for a more concise solution:

for i in range(len(list1)):
    list1[i]['address'] = 'Valid' if '15423' in list1[i]['address'] else 'Invalid'

Both of these print:

[{'time': '2020', 'name': 'one', 'address': 'Valid'},
{'time': '2021', 'name': 'two', 'address': 'Invalid'},
{'time': '2019', 'name': 'five', 'address': 'Valid'}]
user_177698150

you have to loop through the list!

Why?

let's say num_list = [0, 1, 2, 3]

using a for loop like so:

for item in num_list:
    ...

will loop through num_list as you'd expect. item will be set to the current value, in this case, it will set item to 1, do the code in the loop, then set item to 2, then do the code in the loop again, and so on.

now let's say num_list = [{"number": 0}, {"number": 1}, {"number": 2}, {"number": 3}].

this time, if you run the same for loop, item will still be set to the current value, in this case, it will set it to the dictionary instead of the number. thus, item is set to {"number": 0}, then the code inside the loop will run, then item is set to {"number": 1}, then the code inside the loop will run again, etc.

thus, item will be set to a dictionary, which by then you can edit like any other dictionary! simply do item["number"] = ...

for the actual fixed code, here ya go

list1 = [
    {'time': '2020', 'name': 'one', 'address': '15423'},
    {'time': '2021', 'name': 'two', 'address': '8548305'},
    {'time': '2019', 'name': 'five', 'address': '15423'}
]


for item in list1:
    if item["address"] == "15423":
        item["address"] = "Valid"
    else:
        item["address"] = "Invalid"

print(list1)

output:

[
    {'time': '2020', 'name': 'one', 'address': 'Valid'},
    {'time': '2021', 'name': 'two', 'address': 'Invalid'},
    {'time': '2019', 'name': 'five', 'address': 'Valid'}
]
user_171918380

Most of have answered the question. Refer the below solution as well for few points:

You have dictionaries in a list, hence you need to first iterate over each element and access dictionary. While iteration check if address key is present in dictionary or not and then apply the if condition. If we use item['address'] then possibilities are that code might break if we didn't find address key in any of the dictionary. Hence use item.get('address') to extract the value.

Here is the code:

list1 = [
{'time': '2020', 'name': 'one', 'address': '15423'},
{'time': '2021', 'name': 'two', 'address': '8548305'},
{'time': '2019', 'name': 'five', 'address': '15423'}
]


for item in list1:
    if item.get('address'):
         if item.get('address')== "15423":
             item["address"] = "Valid"
         else:
             item["address"] = "Invalid"
print(list1)
user_125431910
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