更に・・・

diff_y = abs(pre_y  - y_test)
print("average=", sum(diff_y) / len(diff_y))
print("max=", max(diff_y))

average= 1.6808867723049854
max= 6.495406725801676

import matplotlib.pyplot as plt
import pandas as pd
# CSVを読み込む ---(*1)
df = pd.read_csv("kion10y.csv", encoding="utf-8")
# 月ごとに平均を求める ---(*2)
g = df.groupby(['月'])["気温"]
gg = g.sum() / g.count()
# 結果を出力 ---(*3)
print(gg)
gg.plot()
plt.savefig("tenki-avr-temp.png")
月
1      5.795308
2      6.326688
3      9.951906
4     14.870606
5     19.705279
6     22.422424
7     26.931085
8     27.702346
9     24.082424
10    18.918768
11    13.326061
12     8.329032
Name: 気温, dtype: float64

import pandas as pd
df = pd.read_csv('kion10y.csv', encoding="utf-8")
atui = (df["気温"] > 30)
cnt = df[atui].groupby(["年"])["年"].count()
print(cnt)
cnt.plot()

年
2008     5
2010    21
2011     9
2012     8
2013    16
2014    12
2015     7
2016     1
2017     1
2018    11
Name: 年, dtype: int64