尝试在python执行中的except语句

Question

Suppose I am making calls to a web api that requires a wait of 4 seconds after the limit is exceeded. Using a try except loop and the time package I can have the program pause if the exception is encountered. If I am working with pandas indices in an iterative loop, will the program pick up where it left off? Example:

i = 0
while i < len(df):
    try:
        df['A'] = df[i:i + 10].apply(lambda x: api_call(x['B'])[0] + 10)
    except IndexError:
        time.sleep(5)
i += 10

If the exception is raised on df[12], after the program has paused for 5 seconds, how do I get the program to pick up at the index that caused the exception (signaling that the program exceeded the number of calls allowed)?

Answer 1

I think you just need an else block on your try...except code.

i = 0
while i < len(df):
    try:
        df['A'] = df[i:i + 10].apply(lambda x: api_call(x['B'])[0] + 10)
    except IndexError:
        time.sleep(5)
    else:
        i += 10

This makes it so that i += 10 only runs if the try block doesn't raise an exception. Otherwise the loop repeats with the same i value.