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Fair Teams Solution

coaches = coaches.sample(frac=1, random_state=2357)
players = players.sample(frac=1, random_state=7532)
repeats = np.ceil(len(players)/len(coaches)).astype('int64')
coaches_repeated = pd.concat([coaches] * repeats).head(len(players))
result = players.copy()
result.index = pd.Index(coaches_repeated, name='coach')

print(result)
# coach
# Stephen       Julian
# Scott         Joshua
# Aaron      Elizabeth
# Joshua         Asher
# Peter         Oliver
# Donald       William
# Stephen        Wyatt
# Scott         Isaiah
# Aaron          Ethan
# Joshua       Madison
# Peter            Leo
# Donald          Ryan
# Stephen     Scarlett
# Scott            Mia
# Aaron         Connor
# Joshua         James
# Peter          Emily
# Donald        Hannah
# Stephen        Layla
# Scott       Isabella
# dtype: string

Explanation

  1. Randomly sort the coaches and players using the Series.sample() method with frac=1, which means "randomly sample 100% of the series values". By default this happens without replacement, so what we're doing is randomly shuffling each Series.

    # randomly shuffle each series
coaches = coaches.sample(frac=1, random_state=2357)
players = players.sample(frac=1, random_state=7532)

print(coaches)
# 5    Stephen
# 4      Scott
# 0      Aaron
# 2     Joshua
# 3      Peter
# 1     Donald
# dtype: string

print(players)
# 10       Julian
# 9        Joshua
# 2     Elizabeth
# 0         Asher
# 15       Oliver
# 18      William
# 19        Wyatt
# 7        Isaiah
# 4         Ethan
# 13      Madison
# 12          Leo
# 16         Ryan
# 17     Scarlett
# 14          Mia
# 1        Connor
# 8         James
# 3         Emily
# 5        Hannah
# 11        Layla
# 6      Isabella
# dtype: string

  2. Repeat the coaches Series until it's at least as long as the players Series. With help from NumPy's ceil() method, we figure we must repeat the coaches Series four times.

    repeats = np.ceil(len(players)/len(coaches)).astype('int64')
print(repeats)  # 4

    We can repeat the Series by wrapping it inside a list and using Python's repetition operator *4.

    [coaches] * repeats
    Note

    This makes a list with four elements, each of which is a reference to the coaches series. The data isn't actually copied four times.

    Then we can use the concat() function to convert the list of Series into a single Series object.

    pd.concat([coaches] * repeats)
# 5    Stephen
# 4      Scott
# 0      Aaron
# 2     Joshua
# 3      Peter
# 1     Donald
# 5    Stephen
# 4      Scott
# ...   .....
# 3      Peter
# 1     Donald
# dtype: string

    This new Series has 24 elements which is slightly longer than our players Series which has 20 elements, so we'll chain it with .head(len(players)) to pick out the first 20 values.

    coaches_repeated = pd.concat([coaches] * repeats).head(len(players))

print(coaches_repeated)
# 5    Stephen
# 4      Scott
# 0      Aaron
# 2     Joshua
# 3      Peter
# 1     Donald
# 5    Stephen
# 4      Scott
# 0      Aaron
# 2     Joshua
# 3      Peter
# 1     Donald
# 5    Stephen
# 4      Scott
# 0      Aaron
# 2     Joshua
# 3      Peter
# 1     Donald
# 5    Stephen
# 4      Scott
# dtype: string

  3. Lastly we copy the players Series into a new Series called result and then set its index equal to the coaches_repeated values we generated in the last step.

    result = players.copy()
result.index = pd.Index(coaches_repeated, name='coach')

print(result)
# coach
# Stephen       Julian
# Scott         Joshua
# Aaron      Elizabeth
# Joshua         Asher
# Peter         Oliver
# Donald       William
# Stephen        Wyatt
# Scott         Isaiah
# Aaron          Ethan
# Joshua       Madison
# Peter            Leo
# Donald          Ryan
# Stephen     Scarlett
# Scott            Mia
# Aaron         Connor
# Joshua         James
# Peter          Emily
# Donald        Hannah
# Stephen        Layla
# Scott       Isabella
# dtype: string

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