def calories_per_portion(input):
    """
    >>> calories_per_portion("For 7 portions your meal has 1752 calories.")
    '250.29'
    >>> calories_per_portion("For 4 portions your meal has 1000 calories.")
    '250.0'
    >>> calories_per_portion("For 1 portions your meal has 1 calories.")
    '1.0'
    >>> calories_per_portion("For 10 portions your meal has 0 calories.")
    '0.0'
    """
    lst = input.split(' ') # list containing the individual words in string
    nums = []   # store numbers of string in list

    for i in range(len(lst)):
        if lst[i].isnumeric():
            nums.append(lst[i])

    return str(round((float(nums[1]) / float(nums[0])), 2))