cs50p/problems/pset1/extensions/extensions.py

extensions = {
    ".gif": "image/gif",
    ".jpg": "image/jpeg",
    ".jpeg": "image/jpeg",
    ".png": "image/png",
    ".pdf": "application/pdf",
    ".txt": "text/plain",
    ".zip": "application/zip"
}

def main():
    file_name = input("Enter file name:\t\t").lower().strip()
    for extension, mime in extensions.items():
        if file_name.endswith(extension):
            print(mime)
            break
    else:
        print("application/octet-stream")


if __name__ == "__main__":
    main()