26  Things I Commonly Forget

26.1 .loc and .iloc

df.loc[df["value"] > 10, ["city", "value"]]
df.iloc[0:5, 0:3]

• .loc uses labels and conditions.
• .iloc uses integer positions.

26.2 Equality and assignment

value = 10
print(value == 10)

True

26.3 Mutable default arguments

Avoid this:

def add_item(item, items=[]):
    items.append(item)
    return items

Prefer this:

def add_item(item, items=None):
    if items is None:
        items = []
    items.append(item)
    return items