python flask request.form.get

request.args: the key/value pairs in the URL query string
request.form: the key/value pairs in the body, from a HTML post form, or JavaScript request that isn't JSON encoded
request.files: the files in the body, which Flask keeps separate from form. HTML forms must use enctype=multipart/form-data or files will not be uploaded.
request.values: combined args and form, preferring args if keys overlap
request.json: parsed JSON data. The request must have the application/json content type, or use request.get_json(force=True) to ignore the content type.

from flask import Flask, request
app = Flask(__name__)

@app.route('/', methods=['GET', 'POST'])
def index():
    data = request.form['input_name']
    ...

search = request.args.get("search")