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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def hash_file(filename):
 """"This function returns the SHA-1 hash of the file passed into it"""


   # make a hash object
   h = hashlib.sha1()

   # open file for reading in binary mode
   with open(filename,'rb') as file:

       # loop till the end of the file
       chunk = 0
       while chunk != b'':
           # read only 1024 bytes at a time
           chunk = file.read(1024)
           h.update(chunk)

   # return the hex representation of digest
   return h.hexdigest()