初学者，编的简单明了
import pandas as pd
df = pd.read_csv(‘newscore.txt’, names=[chr(i) for i in range(65, 65 +4)])
s = df['A'].groupby(by=df['A'].astype(str).str[0:2]).count()
print(s)
import pandas as pd
df = pd.read_csv(‘newscore.txt’, names=[chr(i) for i in range(65, 65 +4)])
s = df['A'].groupby(by=df['A'].astype(str).str[0:2]).count()
print(s)