例2.2统计字符出现的频数

import numpy as np
a = []
with open('data2_2.txt') as f:
    for(i,s) in enumerate(f):
        a.append([a.count('a'),a.count('c'),
                  a.count('g'),a.count('t')])
b = np.array(a)
print(b)
print("学号：3008")

结果如下图