azm-gh

export default function Counter() {
  const [count, setCount] = useState(0);

  function handleClick() {
    setCount(count +1);
  }

  return (
    <button onClick = {handleClick}>
      You pressed me {count} times

azm-gh

import os
from pathlib import Path

with open('data.txt', 'w') as f:
    data = 'some data to be written in a file'
    f.write(data)

with open('data.txt', 'r') as f:
    data = f.read()

azm-gh

import math

class MyClass:
    def method(self):
        return 'instance method called', self

    @classmethod
    def classmethod(cls):
        return 'class method called',cls

azm-gh

import time

def speed_test(func):
    def wrapper(*args, **kwargs):
        t1 = time.time()
        for x in xrange(5000):
            results = func(*args, **kwargs)
        t2 = time.time()
        print '%s took %0.3f ms' % (func.func_name, (t2-t1)*1000.0)
        return results