the python dictionary is fine and printing what i want, printing the dict prints
{'hi': 1, 'hello': 1}
but when i dump it puts the yaml at the end of the file rather than overriding the file

yaml.dump() appending to file rather than overwriting
how do i make set 'hi' to 1 and 'hello' to 1

import yaml

class myClass():
  def __init__(self):
    self.configFile = open('config.yml', 'r+')
    self.config = yaml.load(self.configFile)
    self.config['hi'] = 1
    self.config['hello'] = 1
    yaml.dump(
      self.config,
      self.configFile,
      default_flow_style=False
    ) 
    print(self.config)
    # returns {'hi': 1, 'hello': 1} 
    
myClass()

config file before:

hi: 0
hello: 0

after:

hi: 0
hello: 0
hi: 1
hello 1

what i want:

hi: 1
hello: 1