Question

所以这是我的文本文件，我想计算每年的平均值：

1969    324.000
1970    330.190
1970    326.720
1970    327.130
1971    326.970
1971    331.200
1971    329.430
1971    335.770
1971    337.600

这是我从另一个问题得到的代码，但它仍然存在错误：

In[2]: result = {}
with open('filename.txt', 'r') as f:
       for line in f:
       year, num = line.split()
       year = int(year)
       num = float(num)
       try:
           result[year].append(num)
       except KeyError:
           result[year] = [num]

In[3]: for k, v in sorted(result.items()):
   print('Year: {}\tAverage: {:.2f}'.format(k, sum(v) / len(v)))

我的错误：预计缩进块

Answer 1

好吧，看起来你不想在for循环后打算这条线。

with open('filename.txt', 'r') as f:
    for line in f:
       year, num = line.split()
       ...

Answer 2

如果您有权访问pandas，则该库会提供优化的解决方案。

import pandas as pd
from io import StringIO

mystr = StringIO("""1969    324.000
1970    330.190
1970    326.720
1970    327.130
1971    326.970
1971    331.200
1971    329.430
1971    335.770
1971    337.600""")

df = pd.read_csv(mystr, header=None, names=['Year', 'Amount'],
                 delim_whitespace=True)

res = df.groupby('Year')['Amount'].mean().to_dict()

结果：

{1969: 324.0, 1970: 328.01333333333338, 1971: 332.19400000000007}

从python中的文本文件计算每年的平均值

2 个答案: