How can I pass parameters into a URL for Python requests?

Passing parameters into a URL when using the Python requests library is a common task when interacting with APIs. You can achieve this by using the params argument within the requests functions (get, post, etc.). Here's how you can do it:

1. Using the params Argument:

- The params argument accepts a dictionary or a list of tuples where keys are parameter names and values are the parameter values. The requests library will then properly encode the parameters and append them to the URL.

2. Example with a Dictionary:

- Suppose you want to send parameters like key1=value1 and key2=value2. Here's how you can accomplish it:

import requests

url = "https://example.com/api"
params = {
  "key1": "value1",
  "key2": "value2"
}

response = requests.get(url, params=params)

print(response.url)


- The requests library automatically generates the URL like this: https://example.com/api?key1=value1&key2=value2

3. Example with a List of Tuples:

- If you have duplicate keys, using a list of tuples is preferable. For example:

import requests

url = "https://example.com/api"
params = [
  ("key1", "value1"),
  ("key1", "value2"),
  ("key2", "value3")
]

response = requests.get(url, params=params)

print(response.url)


- This will generate URL like: https://example.com/api?key1=value1&key1=value2&key2=value3

4. Encoding of Parameters:

- requests automatically URL encodes parameters so you don't have to worry about characters like spaces or special symbols. For example, "my key" will be encoded as "my+key" in the URL.

5. When to Use params:

- Use the params argument when you're adding query parameters to a URL, typically with GET requests. For POST requests with data in the request body, you should use the data or json arguments.

6. Using requests.Request:

- You can create a requests.Request object which can also have params set on it.

import requests

url = "https://example.com/api"
params = {
  "key1": "value1",
  "key2": "value2"
}

req = requests.Request('GET', url, params=params).prepare()

session = requests.Session()
response = session.send(req)

print(response.url)

By using the params argument, you can efficiently and correctly pass parameters into your URL when making HTTP requests with Python's requests library. This method ensures proper URL encoding and management of parameters.

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