# To create an empty dictionary, use the built-in dict() function.
m = dict()

# Set key/value pairs using typical name[key] = val syntax.
m["k1"] = 7
m["k2"] = 13

# Printing a map with e.g. print() will show all of its key/value pairs.
print("map:", m)

# Get a value for a key with name[key].
v1 = m["k1"]
print("v1:", v1)

# If the key doesn’t exist, the default value of None is returned.
v3 = m.get("k3", None)
print("v3:", v3)

# The built-in len() function returns the number of key/value pairs when called on a map.
print("len:", len(m))

# The built-in del keyword removes key/value pairs from a map.
del m["k2"]
print("map:", m)

# To remove all key/value pairs from a map, use the clear() method.
m.clear()
print("map:", m)

# The optional second return value when getting a value from a map indicates if the key was present in the map. 
# This can be used to disambiguate between missing keys and keys with default values like 0 or "". 
# Here we didn’t need the value itself, so we used the in keyword.
_, prs = "k2" in m, m.get("k2")
print("prs:", prs)

# You can also declare and initialize a new map in the same line with this syntax.
n = {"foo": 1, "bar": 2}
print("map:", n)

# Python's collections module provides additional utility functions for specialized dictionary types.
from collections import Counter

n2 = {"foo": 1, "bar": 2}
if n == n2:
    print("n == n2")