Что, если вы попробуете это.
import pandas as pd
keys = [i for i in range(1, 7)]
names = ['snake', 'pandas', 'parrot', 'catipie', 'cattie', 'pradip']
df = pd.DataFrame({"key": keys, "name": names})
print(df)
# key name
# 0 1 snake
# 1 2 pandas
# 2 3 parrot
# 3 4 catipie
# 4 5 cattie
# 5 6 pradip
def get_frequency(s):
d = {}
for animal in s:
ch = animal[0]
if ch in d:
d[ch] += 1
else:
d[ch] = 1
return d
data = get_frequency(df['name'])
new_df = pd.DataFrame([[v] for v in data.values()], index=data.keys(), columns=["frequency"]).sort_values(["frequency"], ascending=False)
print(new_df)
# frequency
# p 3
# c 2
# s 1