len() — get length

# Length of sequences:
print(len([1, 2, 3]))  # 3
print(len("hello"))  # 5
print(len({'a': 1, 'b': 2}))  # 2 (number of keys)

sum() — add numbers

numbers = [1, 2, 3, 4, 5]
total = sum(numbers)
print(total)  # 15

# With start value:
total = sum(numbers, 10)  # Start from 10
print(total)  # 25

min() — find minimum

numbers = [3, 1, 4, 1, 5]
smallest = min(numbers)
print(smallest)  # 1

# With key function:
words = ['apple', 'pie', 'a']
shortest = min(words, key=len)
print(shortest)  # 'a'

max() — find maximum

numbers = [3, 1, 4, 1, 5]
largest = max(numbers)
print(largest)  # 5

# With key function:
words = ['apple', 'pie', 'banana']
longest = max(words, key=len)
print(longest)  # 'banana'

Multiple arguments

# Can pass multiple values:
print(min(3, 1, 4))  # 1
print(max(3, 1, 4))  # 4
print(sum([1, 2], [3, 4]))  # Error! sum only works with numbers