Django filter by multiple filters , checking for certain conditions

Question

I need to check for a number of conditions and do a filter OR search if the conditions are specified. I am doing it as below:

def or_q_if_truthfull(**kwargs):
    filtered = [Q(**{k: v}) for k, v in kwargs.items() if v]
    if filtered:
        return reduce(or_,filtered)
    else:
        return Q()
def check():        
    if age.isdigit():
        my_q = or_q_if_truthfull(
            name__lower__contains=name.lower(),
            age=age,
            mobile__contains=phone,
            email__lower__contains=email.lower(),
            address__lower__contains=address.lower(),
            city__lower__contains=city.lower(),
        )
    else:
        my_q = or_q_if_truthfull(
            name__lower__contains=name.lower(),
            mobile__contains=phone,
            email__lower__contains=email.lower(),
            address__lower__contains=address.lower(),
            city__lower__contains=city.lower(),
        )

I tried to combine the if and else into one block:

Method 1:

my_q = or_q_if_truthfull(
    name__lower__contains=name.lower(),
    age=age if age.isdigit(),
    mobile__contains=mobile,
    alternate__contains=alternate,
    email__lower__contains=email.lower() if email else email,
    address__lower__contains=address.lower(),
    city__lower__contains=city.lower(),
)

File "/home/joel/myappointments/clinic/views.py", line 97
age=age if age.isdigit(),
                        ^
SyntaxError: invalid syntax

Then I tried this:

Method 2:

from numbers import Number
my_q = or_q_if_truthfull(
    cstid=HospitalID,
    name__lower__contains=name.lower() if name else name,
    age=age if isinstance(age, Number),
    mobile__contains=mobile,
    alternate__contains=alternate,
    email__lower__contains=email.lower() if email else email,
    address__lower__contains=address.lower(),
    city__lower__contains=city.lower(),
)

File "/home/joel/myappointments/clinic/views.py", line 97
    age=age if isinstance(age, Number),
                                    ^
SyntaxError: invalid syntax

What's the issue in the two methods I tried? Can you suggest a minimalistic solution?

Please improve the title and split your question in two distinct questions if that better fits. It's easier for us to provide good answers for one question at a time. — Frederik.L, Sep 13 '18 at 06:34
I wanted one good solution. I thought it would be better if I provided the different methods I tried. I'll change the title. — Joel G Mathew, Sep 13 '18 at 06:36
Then your title is suggesting the wrong thing. There is one problem but two different approaches you've tried to address it. Your question would benefit from being more descriptive of the issue you are having. — Frederik.L, Sep 13 '18 at 06:37

score 1 · Accepted Answer · answered Sep 13 '18 at 06:45

1

In python, you can use the None keyword to make a variable hold no value.

For merging, you could go with something like this:

my_q = or_q_if_truthfull(
    name__lower__contains=name.lower(),
    age=age if age.isdigit() else None,
    mobile__contains=phone,
    email__lower__contains=email.lower(),
    address__lower__contains=address.lower(),
    city__lower__contains=city.lower(),
)

answered Sep 13 '18 at 06:45

Frederik.L

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So the else part is mandatory, contrary to block type if loops ? – Joel G Mathew Sep 13 '18 at 06:49
1

@Droidzone Yes, this is mandatory that when you use operator = to assign a value, there is an actual assignation in every path. – Frederik.L Sep 13 '18 at 06:52
1

@Droidzone: yes, this `age if age.isdigit() else None` is *not* an `if`-block, it is a ternary operator, that looks a bit similar. – Willem Van Onsem Sep 13 '18 at 07:10

Django filter by multiple filters , checking for certain conditions

1 Answers1