Loading spinner in python

loading_spinner.py

import sys
import time

from itertools import cycle
from multiprocessing import Process


class UnixLoading:
  def __enter__(self):
    def thread(self):
      for char in itertools.cycle("|/-\\"):
        sys.stdout.write(f"{char} Loading\r")
        sys.stdout.flush()

        time.sleep(0.29)
    
    self.thread = multiprocessing.Process(
      target = thread,
      args = (self,),
      daemon = True
    )
    self.started = int(str(time.clock_gettime_ns(0))[0:13])
    
    self.thread.start()
    
  def __exit__(self, _type, value, traceback):
    self.thread.terminate()
    self.ended = int(str(time.clock_gettime_ns(0))[0:13])
    
    if _type is not None:
      sys.stdout.write("❌ Error after %s seconds.\n\r" % \
        abs((self.started - self.ended) / 1000)
      )
      sys.stdout.flush()
    else:
      sys.stdout.write("✅ Success. (lasted %s seconds.)\n\r" % \
        abs((self.started - self.ended) / 1000)
      )
      sys.stdout.flush()
      
    return None

loading_spinner_example.py

with Loading():
  # some heavy calculations