Hey there! Let's tackle your two questions step by step— I’ve worked through similar scenarios countless times, so I’ll share practical, hands-on methods here.

You’ve got a few reliable ways to figure this out, depending on how direct you want to be:

• Check the Content-Type response header
  Servers almost always send a Content-Type header that tells you exactly what format the response is in. You can pull this with requests like so:

  import requests
  
  url = "https://api.coinmarketcap.com/v1/ticker/"
  response = requests.get(url)
  content_type = response.headers.get("Content-Type")
  print(content_type)
  

  For the CoinMarketCap API, this will return something like application/json; charset=utf-8—which means it’s JSON data. Other common values include text/html (HTML pages) or text/plain (raw text).

• Try parsing as JSON directly
  If you suspect the data is JSON, use response.json() to attempt parsing. If it works, you’ve confirmed the format; if it throws a ValueError, it’s definitely not JSON:

  try:
      parsed_data = response.json()
      print("Response is JSON-formatted!")
  except ValueError:
      print("Response isn't JSON—check if it's plain text, HTML, or another format.")
  

• Peek at the raw response text
  If you’re still unsure, print the first few characters of the response text to spot patterns:

  print(response.text[:100])  # Show first 100 characters
  

  JSON will start with [ or {, HTML will start with <, and plain text will have no obvious markup.

First, let’s note that this specific API is a GET endpoint, so it doesn’t require a request body (like POST data). But if you’re asking about query parameters or the structure of data you might need to send (for other endpoints), here’s how to investigate:

• Send a basic request and inspect the response
  The easiest way to understand what this API accepts is to send a simple GET request and look at what it returns. For example:

  import requests
  
  url = "https://api.coinmarketcap.com/v1/ticker/"
  response = requests.get(url)
  data = response.json()
  
  # Look at the first entry to see the data structure
  print("Sample entry from the API:")
  print(data[0])
  

  This will show you each crypto entry has fields like id, name, symbol, price_usd, etc. If you want to filter results, you can test query parameters:

  # Request only the top 5 cryptocurrencies
  params = {"limit": 5}
  filtered_response = requests.get(url, params=params)
  print(len(filtered_response.json()))  # Should return 5
  

• Test parameter variations
  If you want to target a specific crypto, try appending its id (from the response) to the URL:

  bitcoin_url = "https://api.coinmarketcap.com/v1/ticker/bitcoin/"
  btc_data = requests.get(bitcoin_url).json()
  print(btc_data[0]["name"])  # Should print "Bitcoin"
  

  This tells you the API accepts individual crypto IDs as URL path parameters.

• Use error messages as clues
  If you were working with a POST endpoint that required a request body, sending invalid data (like plain text instead of JSON) would trigger an error response that usually spells out the required format. For example, an API might return {"error": "Request body must be valid JSON"} to guide you.

Hope these practical steps help you navigate these requests smoothly!

内容的提问来源于stack exchange，提问作者lizzie hopkins