How to avoid writing request.GET.get() twice in order to print it?

givp_71809 0
Viewed 32593

I come from a PHP background and would like to know if there's a way to do this in Python.

In PHP you can kill 2 birds with one stone like this:

Instead of:

if(getData()){
    $data = getData();
    echo $data;
}

I can do this:

if($data = getData()){
    echo $data;
}

You check to see if getData() exists AND if it does, you assign it to a variable in one statement.

I wanted to know if there's a way to do this in Python? So instead of doing this:

if request.GET.get('q'):
    q = request.GET.get('q')
    print q

avoid writing request.GET.get('q') twice.

if-statement dictionary python
10 Answers

PEP 572 introduces Assignment Expressions. From Python 3.8 and onwards you can write:

if q := request.GET.get('q'):
    print q

Here are some more examples from the Syntax and semantics part of the PEP:

# Handle a matched regex
if (match := pattern.search(data)) is not None:
    # Do something with match

# A loop that can't be trivially rewritten using 2-arg iter()
while chunk := file.read(8192):
   process(chunk)

# Reuse a value that's expensive to compute
[y := f(x), y**2, y**3]

# Share a subexpression between a comprehension filter clause and its output
filtered_data = [y for x in data if (y := f(x)) is not None]
user_36200030
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