It is better to use urlencode here. Not much difference for single parameter but IMHO makes the code clearer. (It looks confusing to see a function quote_plus! especially those coming from other languates)
In [21]: query='lskdfj/sdfkjdf/ksdfj skfj'
In [22]: val=34
In [23]: from urllib.parse import urlencode
In [24]: encoded = urlencode(dict(p=query,val=val))
In [25]: print(f"http://example.com?{encoded}")
http://example.com?p=lskdfj%2Fsdfkjdf%2Fksdfj+skfj&val=34
urlencode: https://docs.python.org/3/library/urllib.parse.html#urllib.parse.urlencode
quote_plus: https://docs.python.org/3/library/urllib.parse.html#urllib.parse.quote_plus