在python中动态生成URL

Question

I would like to programatically generate a URL made by these parts

Fixed part

https://booking.snav.it/#/booking/rates/

Outbound route number - changes

1040

Outbound date - changes

19-02-2019

Inbound route number - changes

1042

Inbound date - changes

20-02-2019

Parameters:

"adults": "1"
"childs":"0"
"infants":"0"
"res": "0"
"vehicle":"0"

Output

https://booking.snav.it/#/booking/rates/1040/19-02-2019/1042/19-02-2019?adults=1&childs=0&infants=0&res=0&vehicle=0

I know how to pass parameters with urllib.parse.urlencode

params = urllib.parse.urlencode({
   "adults": "1"
    "childs":"0"
    "infants":"0"
    "res": "0"
    "vehicle":"0"
})

url = "https://booking.snav.it/#/booking/rates/"
res = requests.get(url, params=params)

but don't know how to build dynamically the first part after the fixed URL 1040/19-02-2019/1042/19-02-2019

Answer 1

A URL is really just a string, any of the usual string manipulation techniques would do here. Your component parts don't have any characters in them that would require URL-encoding here either, making the whole process simpler.

If you do have component parts that use characters that are not in the list of unreserved characters , then use the urllib.parse.quote() function to convert those characters to URL-safe components.

You could use str.join() with / to join string parts:

outbound_route = '1040'
outbound_date = '19-02-2019'
inbound_route = '1042'
inbound_date = '20-02-2019'

url = "https://booking.snav.it/#/booking/rates"  # no trailing /
final_url = '/'.join([url, outbound_route, outbound_date, inbound_route, inbound_date])

or you could use a formatted string literal :

url = "https://booking.snav.it/#/booking/rates/"
final_url = f'{url}{outbound_route}/{outbound_date}/{inbound_route}/{inbound_date}'

This approach has the advantage that the components don't have to be strings; if outbound_route and inbound_route are integers, you don't have to explicitly convert them to strings first.

Or, since URL paths work a lot like POSIX filesystem paths, you could use the pathlib.PosixPurePath() class to contruct the path:

from pathlib import PosixPurePath

path = PosixPurePath('/booking/rates') / outbound_route / outbound_date / inbound_route / inbound_date
final_url = f"https://booking.snav.it/#{path}"

In all cases, you end up with a final URL to use in requests :

res = requests.get(final_url, params=params)