Krdytkyu

I'm generating a URL (in string) that depends on 3 optional parameters, file, user and active.

From a base url: /hey I want to generate the endpoint, this means:

• If file is specificied, my desired output would is: /hey?file=example
  


• If file and user is specified, my desired output is: /hey?file=example&user=boo
  


• If user and active are specified, my desired output is: /hey?user=boo&active=1


• If no optional parameters are specified, my desired output is: /hey
  


• and so on with all the combinations...

My code, which is working correctly, is as follows (change the None's at the top if you want to test it):

file = None

user = None

active = 1



ep = "/hey"

isFirst = True



if file:

  if isFirst:

    ep+= "?file=" + file;

    isFirst = False;

  else: ep += "&file=" + file;



if user:

  if isFirst:

    ep+= "?user=" + user;

    isFirst = False;

  else: ep += "&user=" + user;



if active:

  if isFirst:

    ep+= "?active=" + str(active);

    isFirst = False;

  else: ep += "&active=" + str(active);



print ep

Can someone give me a more python implementation for this? I can't use modules as requests.

Thanks in advance.

The most Pythonic version of this depends a bit on what you do with that URL afterwards. If you are using the requests module (which you probably should), this is already built-in by specifying the params keyword:

import requests



URL = "https://example.com/"



r1 = requests.get(URL, params={"file": "example"})

print(r1.url)

# https://example.com/?file=example



r2 = requests.get(URL, params={"file": "example", "user": "boo"})

print(r2.url)

# https://example.com/?file=example&user=boo



r3 = requests.get(URL, params={"user": "boo", "active": 1})

print(r3.url)

# https://example.com/?user=boo&active=1



r4 = requests.get(URL, params={})

print(r4.url)

# https://example.com/

If you do need a pure Python solution, this is what I would do:

def get_url(base_url, **kwargs):

    if not kwargs:

        return base_url

    params = "&".join(f"{key}={value}" for key, value in kwargs.items())

    return base_url + "/?" + params

To be a bit safer, you might want to use urllib.urlencode on the values to ensure that spaces etc are correctly translated (requests does that for you, so there it is not needed).

Example usage:

print(get_url("/hey", file="example"))

# /hey/?file=example



print(get_url("/hey", file="example", user="boo"))

# /hey/?file=example&user=boo



print(get_url("/hey", user="boo", active=1))

# /hey/?user=boo&active=1



print(get_url("/hey"))

# /hey

You're pretty much reinventing urllib.parse.urlencode:

from urllib.parse import urlencode





def prepare_query_string(**kwargs):

    return urlencode([(key, value) for key, value in kwargs.items() if value is not None])

Usage being:

>>> prepare_query_string(active=1)

'active=1'

>>> prepare_query_string(active=1, user=None)

'active=1'

>>> prepare_query_string(active=1, user='bob')

'active=1&user=bob'

>>> prepare_query_string(file='foo.tar.gz', user='bob')

'file=foo.tar.gz&user=bob'

>>> prepare_query_string(file='foo.tar.gz', user='bob', active=None)

'file=foo.tar.gz&user=bob'

>>> prepare_query_string(file='foo.tar.gz', user='bob', active=1)

'file=foo.tar.gz&user=bob&active=1'