Python round and banker’s rounding: Why round(2.5) returns 2

“round” rounds Python numbers:

round(1.3)  # 1
round(1.6)  # 2
round(1.61, 1) # 1.6
round(1.66, 1) # 1.7

Remember, .5 goes to the nearest *even* value:

round(1.5) # 2
round(2.5) # 2, yes 2! 🤯
round(3.5) # 4
round(1.65, 1)  # 1.6
round(2.65, 1)  # 2.6 🤯
round(3.65, 1)  # 3.6