In Python 3+, one can URL-encode any string using the urllib.parse.quote() (alternatively, you could use requests.utils.quote(), which is essentially using the same quote() function from urllib.parse module). This function is intended for quoting the path section of a URL, not the whole URL. It will essentially replace any special characters in a string using the %xx escape. In Python 2.x, the quote() function can be accessed directly from the urllib package, i.e., urllib.quote().

Note that the quote() function considers / characters safe by default. Hence, in case you are passing another URL to the path section (or the query string) of the URL and would like to encode / characters as well, you could do so by setting the safe parameter to '', i.e., an empty string.

Example

Copyimport requests
from urllib.parse import quote 

base_url = 'https://example.com/'
path_param = 'https://raw.githubusercontent.com/ultralytics/yolov5/master/data/images/zidane.jpg'
url = base_url + quote(path_param, safe='')
r = requests.get(url)
print(r.request.url)

Short answer with example:

Copyimport requests

the_data = {"aaa": 1, "bbb": 2, "ccc": "yeah"}
headers = {'Content-Type': 'application/x-www-form-urlencoded'}
# Execute the post
requests.post("http://bla.bla.example.com", data=the_data, headers=headers)
# You have POSTed this HTTP body: aaa=1&bbb=2&ccc=yeah (note, although the content-type is called urlencoded the data is not in the URL but in the http body)
# to this url: "http://bla.bla.example.com"

Requests library does all the JSON to urlencoded string conversion for you

References:

MDN Web docs, Requests lib post url-encoded form