Python爬虫发送Request Body数据咨询：VBA转Python入门问题

Hey there! As someone who’s got solid VBA/WinHTTP experience and is just dipping their toes into Python for web scraping, I get how it can feel a bit overwhelming at first. Let’s break down how to send request bodies in Python—starting with the most straightforward, beginner-friendly tools that’ll feel familiar to your existing workflow.

First off, forget the low-level urllib module for now—requests is the Python equivalent of WinHTTP, but way more intuitive and less verbose. It’s the go-to library for almost all web scraping/API tasks, so let’s start there.

Step 1: Install the Requests Library #

First, install it via pip (Python’s package manager) if you haven’t already:

pip install requests

Common Request Body Scenarios (With Code Examples) #

Let’s cover the most common cases you’d encounter, mapped to what you might already do in VBA:

1. Sending JSON Formatted Bodies #

This is like when you’d construct a JSON string in VBA and send it with WinHTTP, setting the Content-Type: application/json header. In Python, requests handles the serialization and header setup automatically.

import requests

# Define your payload as a Python dictionary (way easier than building strings in VBA!)
payload = {
    "product_id": 12345,
    "quantity": 2,
    "customer_details": {
        "name": "John Doe",
        "email": "john@example.com"
    }
}

# Send the POST request—note the `json` parameter instead of `data`
response = requests.post("https://example.com/api/place-order", json=payload)

# Check the response (equivalent to WinHTTP's responseText)
print("Response Status Code:", response.status_code)
print("Response Content:", response.text)

2. Sending Form-Encoded Bodies (application/x-www-form-urlencoded) #

This is the standard form submission format—like when you’d send a string like username=foo&password=bar in VBA. Again, requests simplifies this:

import requests

# Form data as a dictionary
payload = {
    "username": "your_username",
    "password": "your_secure_password"
}

# Use the `data` parameter here—requests sets the correct Content-Type automatically
response = requests.post("https://example.com/login", data=payload)

# Access the response just like before
print(response.text)

3. Sending Multipart Form Data (For File Uploads or Mixed Data) #

If you’ve ever had to upload files via VBA (a huge pain!), Python makes this trivial. This is for multipart/form-data requests, which combine regular form fields and file attachments.

import requests

# Regular form fields
form_data = {
    "upload_description": "This is a test text file"
}

# Define the file to upload—use `open()` in read-binary mode
# Pro tip: Use a `with` statement to auto-close the file after the request
with open("test_file.txt", "rb") as file_to_upload:
    files = {"file": file_to_upload}
    # Send the request with both `data` (form fields) and `files` (attachments)
    response = requests.post("https://example.com/upload", data=form_data, files=files)

print(response.text)

4. Custom Raw Request Bodies #

If you ever need to send a raw string (like a custom format that doesn’t fit JSON or form data), you can do that too—similar to how you’d send a raw string in WinHTTP:

import requests

# Your custom body string
raw_body = "custom_key=custom_value&special_format=yes"

# Manually set the Content-Type header
headers = {
    "Content-Type": "application/x-www-form-urlencoded"
}

# Send with the `data` parameter and your custom headers
response = requests.post("https://example.com/custom-endpoint", data=raw_body, headers=headers)

print(response.text)

Bonus: Adding Custom Headers (Like User-Agent or Auth Tokens) #

Just like in VBA where you’d use WinHttpRequest.SetRequestHeader, you can add custom headers in requests with a dictionary:

import requests

headers = {
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36",
    "Authorization": "Bearer your_auth_token_here"
}

payload = {"key": "value"}
response = requests.post("https://example.com/api", json=payload, headers=headers)

Final Notes for VBA Users #

• Unlike VBA’s single-threaded limitation, Python has great async options later on (like aiohttp) if you need to send multiple requests in parallel—but start with requests first to get the basics down.
• requests handles cookies, redirects, and error handling way more gracefully than WinHTTP, so you’ll spend less time debugging low-level issues.

内容的提问来源于stack exchange，提问作者Singularity20XX