For those who are in trouble because NFC is read infinitely when reading NFC with Python

I won't write much in detail, but a memo

For those who want to read NFC in Python

I was in trouble because the ʻon-connectfunction was executed all the time the NFC was in contact. It's not good to putSleep`, and the solution memo that I got by wandering the sea of the net

import nfc

def on_connect(tag):

def on_release(tag):
    print("[*] released:")

def main():
        with nfc.ContactlessFrontend('usb') as clf:
            while clf.connect(rdwr={
                'on-connect': on_connect,
                'on-release': on_release,
    except IOError:
        print("NFC reader connection Error")

if __name__ == '__main__':

This will execute ʻon_connect () only once when the reader and NFC contact, and execute ʻon_release () when they are released.

I saw an infinite number of people who were in trouble if only ʻon-releasewas not executed, or if they didn't entersleep` and kept being called. I would be happy if I could rescue such a person

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