在数据框中将表示为对象的数字更改为长格式或其他格式

Question

因此，我正在使用python 3.6.5，并具有如下所示的数据框，但尺寸更大。

           Date     Open     High      Low    Close         Volume             
0    2018-04-16  8337.57  8371.15  7925.73  8058.67  5,631,310,000   \
1    2018-04-15  7999.33  8338.42  7999.33  8329.11  5,244,480,000   
2    2018-04-14  7874.67  8140.71  7846.00  7986.24  5,191,430,000

           Market Cap  
0     141,571,000,000  
1     135,812,000,000  
2     133,682,000,000  

我能够绘制不同的列：打开，高，低，关闭

但无法显示数量和市值

df.plot(x='Date', y = 'Volume', kind = 'line')

TypeError: Empty 'DataFrame': no numeric data to plot

也在跑步时

df.plot()

ValueError: view limit minimum -36839.658058149995 is less than 1 and is an invalid Matplotlib date value. This often happens if you pass a non-datetime value to an axis that has datetime units

但我可以肯定df ['Date']是日期时间对象

print(df.dtypes)

Date          datetime64[ns]
Open                 float64
High                 float64
Low                  float64
Close                float64
Volume                object
Market Cap            object
dtype: object

Answer 1

要转换object类型列，可以使用：

df['Market Cap'] = df['Market Cap'].str.replace(',', '').astype(float)
df['Volume'] = df['Volume'].str.replace(',', '').astype(float)