What do the square brackets around parameters mean in the official documentation?

Question

I don't know how to interpret this notation:

timedelta([days[, seconds[, microseconds[, milliseconds[, minutes[, hours[, weeks]]]]]]])

Source: https://docs.python.org/2/library/datetime.html#timedelta-objects

I'm using this function with a single keyword argument without inconvenience but I can't understand the reason of this notation ¿Does it have a name? Sorry if this is a duplicate post but I don't know how to google it.

Much better! Thank you @Andy – Juan David Jul 05 '16 at 17:45 — Juan David, Jul 05 '16 at 17:45

score 10 · Accepted Answer · answered Jul 05 '16 at 17:39

This notation is described in the documentation introduction:

a phrase enclosed in square brackets ([ ]) means zero or one occurrences (in other words, the enclosed phrase is optional).

The documentation you link to also explains the parameters:

All arguments are optional and default to 0. Arguments may be ints, longs, or floats, and may be positive or negative.

The short version: If a parameter is enclosed in square brackets, it is optional.

What do the square brackets around parameters mean in the official documentation?

1 Answers1