input: Write a function to generate sample data for a web application using Python's faker library. The output should contain three columns of data: name, email, and age. If the number of rows to generate is not specified, default to generating 10 rows.
  from faker import Faker
  
  def generate_sample_data(num_rows=10):
   fake = Faker()
   for _ in range(num_rows):
    print(fake.name(), fake.email(), fake.random_int(min=18, max=60))
  
  assert generate_sample_data(5) # Should print 3 sets of data
  assert generate_sample_data() # By default, it should print 10 sets of data
output: def generate_sample_data(num_rows=10):
   fake = Faker()
   data = []
   for _ in range(num_rows):
    data.append((fake.name(), fake.email(), fake.random_int(min=18, max=60)))
   return data