input: Write a function that rewrites the given Python code snippet by using list comprehensions. The original code collects even numbers from 1 to 20 into a list. The function should return the rewritten code as a string.
  assert rewrite_with_list_comprehension("even_numbers = []\nfor i in range(1,21):\n    if i % 2 == 0:\n        even_numbers.append(i)")=="even_numbers = [i for i in range(1, 21) if i % 2 == 0]"
  assert rewrite_with_list_comprehension("odd_numbers = []\nfor j in range(1,11):\n    if j % 2 != 0:\n        odd_numbers.append(j)")=="odd_numbers = [j for j in range(1, 11) if j % 2 != 0]"
  assert rewrite_with_list_comprehension("squares = []\nfor k in range(1,6):\n    squares.append(k**2)")=="squares = [k**2 for k in range(1, 6)]"
  assert rewrite_with_list_comprehension("")==""
output: def rewrite_with_list_comprehension(code):
      lines = code.strip().split('\n')
      if not lines:
          return ""
      var_name = lines[0].split('=')[0].strip()
      loop_var = lines[1].split(' ')[1]
      start, end = lines[1].split('range(')[1].split(')')[0].split(',')
      condition = lines[2].strip() if len(lines) > 2 else ""
      append_value = lines[3].split('.append(')[1].split(')')[0] if condition else loop_var
      
      if condition:
          return f"{var_name} = [{append_value} for {loop_var} in range({start}, {end}) if {condition.split('if ')[1]}]"
      else:
          return f"{var_name} = [{append_value} for {loop_var} in range({start}, {end})]"