Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Selected Reading
How to send the result of Python CGI script to the browser?
A Python CGI script runs on a web server and sends dynamic HTML content to the browser. To send results from your CGI script to the browser, you need to output proper HTTP headers followed by HTML content.
Basic CGI Response Structure
Every CGI script must start with a content-type header, followed by a blank line, then the HTML content ?
#!/usr/bin/env python3
import cgi
# Create instance of FieldStorage
form = cgi.FieldStorage()
# Get data from HTML form fields
first_name = form.getvalue('first_name')
last_name = form.getvalue('last_name')
# Send HTTP header
print("Content-type:text/html")
print() # Blank line required
# Send HTML content
print("<html>")
print("<head>")
print("<title>Hello - Second CGI Program</title>")
print("</head>")
print("<body>")
print("<h2>Hello %s %s</h2>" % (first_name, last_name))
print("</body>")
print("</html>")
Complete CGI Script Example
Here's a complete working CGI script that processes form data and sends formatted results ?
#!/usr/bin/env python3
import cgi
import cgitb
# Enable CGI error reporting
cgitb.enable()
# Create instance of FieldStorage
form = cgi.FieldStorage()
# Get form data
first_name = form.getvalue('first_name', 'Unknown')
last_name = form.getvalue('last_name', 'User')
# Send content-type header
print("Content-type:text/html\r\n\r\n")
# Generate HTML response
print("""
<!DOCTYPE html>
<html>
<head>
<title>CGI Response</title>
<style>
body { font-family: Arial, sans-serif; margin: 50px; }
.greeting { color: #333; background: #f0f0f0; padding: 20px; }
</style>
</head>
<body>
<div class="greeting">
<h2>Hello %s %s!</h2>
<p>Welcome to our CGI application.</p>
</div>
</body>
</html>
""" % (first_name, last_name))
Key Points
- The
Content-typeheader tells the browser what type of content to expect - A blank line must separate the headers from the HTML content
- Use
form.getvalue()to safely retrieve form data with optional default values - Enable
cgitbfor better error debugging during development - HTML-encode user input to prevent XSS attacks in production applications
HTTP Headers for Different Content Types
| Content Type | Header | Use Case |
|---|---|---|
| HTML | Content-type:text/html |
Web pages |
| JSON | Content-type:application/json |
API responses |
| Plain Text | Content-type:text/plain |
Simple text output |
| XML | Content-type:text/xml |
XML documents |
Conclusion
To send CGI script results to the browser, always start with the proper Content-type header, add a blank line, then output your HTML content. Use cgi.FieldStorage() to safely handle form data and consider enabling cgitb for debugging.
Updated on: 2026-03-24T20:02:35+05:30
345 Views
Advertisements