Python: Lists & Dictionaries

What you will learn

How to work with ordered collections (lists) and key-value mappings (dictionaries).

Lists (ordered, mutable)

fruits = ["apple", "banana", "cherry"]
fruits.append("date")       # add to end
fruits.insert(1, "apricot") # insert at index 1
fruits.pop()                # remove and return last
fruits.sort()               # sort in-place
len(fruits)                 # number of elements
fruits[0]                   # first element
fruits[-1]                  # last element

Lists are zero-indexed. Negative indices count from the end.

Dictionaries

user = {
    "name": "Alice",
    "age": 25,
    "skills": ["Python", "SQL"]
}
print(user["name"])        # "Alice"
user["lang"] = "Python"    # add new key
user.get("missing", "N/A") # safe access with default
del user["age"]            # remove key
user.keys()                # view all keys

Quick check below!