Answer:
f = open('client_list.txt', 'a+')
Explanation:
The question is answered in python.
The syntax to open a file is:
file-object-variable-name = open('file-name','file-mode')
In this question:
The file-object-variable-name is f
The file-name is client_list.txt
The file mode is a+ which means to append.
Hence, the statement that does the instruction in the question is:
f = open('client_list.txt', 'a+') or f = open("client_list.txt", "a+")
