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Python

Initialization​

Set and dict​

When initializing a empty set or dict in Python, it's better to implicitly say if it's a set or dict instead of using {} (which is a dict btw).

There are a few benefits in doing so:

  • It's more readable.
  • It's less likely to catch you off guard when you want to use set.
# Do
my_set = set()
my_dict = dict()

# Don't
# This will be a dict and might catch you off guard
my_what = {}

List​

Size copy​

Size copy a list and fill with elements:

my_list = [0 for i in range(other_list)]

my_list = [0] * len(other_list)

With custom first several elements:

my_list = [0, 1] + [0] * len(other_list[2:])
tip

This can be useful for DP-based problems.