從讀取的csv文件中對數據進行處理，求最大值、最小值、平均值等等

1.問題說明

輸出數據集的基本信息,比如最大值，最小值，平均值等

統計確實的變量和樣本個數

通過箱式圖判斷異常點

2.求最大值、最小值和平均值

求最大值:

import pandas as pd
import numpy as np
data = pd.read_csv("C:\\Users\\Administrator\\Desktop\\catering_sale.csv")
data1 = data.describe()
print(data1.max())

運行結果:

銷量    9106.44
dtype: float64

求最小值:

import pandas as pd
import numpy as np
data = pd.read_csv("C:\\Users\\Administrator\\Desktop\\catering_sale.csv")
data1 = data.describe()
print(data1.min())

運行結果:

銷量    22.0
dtype: float64

求平均值:

import pandas as pd
import numpy as np
data = pd.read_csv("C:\\Users\\Administrator\\Desktop\\catering_sale.csv")
data1 = data.describe()
print(data1.mean())

運行結果:

銷量    2621.079309
dtype: float64

3.缺失值的數量

import pandas as pd
import numpy as np
data = pd.read_csv("C:\\Users\\Administrator\\Desktop\\catering_sale.csv")
data2 = data.isnull().sum()
print(data2)

運行結果:

日期    0
銷量    1
dtype: int64

4.箱式圖判斷異常點

plt.figure()
plt.rcParams['font.sans-serif']=[u'SimHei']
plt.rcParams['axes.unicode_minus']=False
p = data.boxplot(return_type='dict')  #畫箱式圖
x = p['fliers'][0].get_xdata()
y = p['fliers'][0].get_ydata()
y.sort()
for i in range(len(x)):
  if i > 0:
    plt.annotate(y[i], xy=(x[i], y[i]), xytext=(x[i]+0.05 - 0.8/(y[i]-y[i-1]), y[i]))
  else:
    plt.annotate(y[i], xy=(x[i], y[i]), xytext=(x[i]+0.08, y[i]))
plt.show()

運行結果:

5.完整代碼

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt #導入圖像庫
data = pd.read_csv("C:\\Users\\Administrator\\Desktop\\catering_sale.csv")
data1 = data.describe()
data2 = data.isnull().sum()
print(data1.mean())
print(data2)
plt.figure()
plt.rcParams['font.sans-serif']=[u'SimHei']
plt.rcParams['axes.unicode_minus']=False
p = data.boxplot(return_type='dict')  #畫箱式圖
x = p['fliers'][0].get_xdata()
y = p['fliers'][0].get_ydata()
y.sort()
for i in range(len(x)):
  if i > 0:
    plt.annotate(y[i], xy=(x[i], y[i]), xytext=(x[i]+0.05 - 0.8/(y[i]-y[i-1]), y[i]))
  else:
    plt.annotate(y[i], xy=(x[i], y[i]), xytext=(x[i]+0.08, y[i]))
plt.show()