Final answer:
The 'calc_avg(L1)' function accepts one argument, which is indicated by the single parameter inside the parentheses. This 'L1' may represent a list or array that the function uses to compute an average.
Step-by-step explanation:
The function calc_avg(L1) accepts a single argument. In programming, arguments are the values that a function takes when it is called. The notation used here, with a single parameter inside the parentheses, signifies that this function is designed to take one argument which is L1 in this case. This could typically represent a list or array of numbers for which the function will calculate an average. It's important to note that while a single argument is accepted, the argument itself could be a complex data structure containing multiple values.