most frequent word

# assuming you have already created a dictionary like this one
# tallying word frequencies

d = {
    'dog': 4,
    'cat': 3,
    'the': 3,
    'chases': 2,
    'why': 1
}

# method 1
# most Pythonic, but doesn't "show its work", so a leap of logic needed
# use max to select the word that has the highest value directly

# this works by saying 'the key for determining max-ness is d.get,'
# i.e. what we get when we look up the item in d, i.e. its value.

# easiest by far in Python but because of its compactness it may be
# instructive to read the other methods

most_freq_word = max(d, key=d.get)
print(most_freq_word)

# method 2
# most intuitive
# iterate through keys, keeping track of the highest value

highest_freq = 0
most_freq_word = ''
for word in d:
    freq = d[word]
    if freq > highest_freq:
        most_freq_word = word
        highest_freq = freq
print(most_freq_word)

# method 3
# invert the dictionary (swap values and keys)
# then use max() to pick the highest value

# NOTE: because there can be ties, each new value needs to be a list;
# here's what it would look like:

"""
d_inverted = {
  4: ['dog'],
  3: ['cat', 'the'],    # <-- note the tie here, hence the lists
  2: ['chases'],
  1: ['why']
}
"""

d_inverted = {}
for word in d:
    freq = d[word]
    if freq not in d_inverted:
        d_inverted[freq] = []
    d_inverted[freq].append(word)

highest_freq = max(d_inverted)
most_freq_word = d_inverted[highest_freq][0] # [0] because it's a list
print(most_freq_word)