在pandas中用一个常量值乘以列。E型

Question

我有一个数据帧：

Event          Modelled flow (cfs)   Observed Flow (cfs)
Event 01           0.8610723               2.105263
Event 01           0.8596087               2.383901
Event 01           0.8749821               2.092879
Event 01           0.9045072               2.119195
Event 01           0.9267832               2.156347
Event 01           0.9156083               1.883901

我想通过将现有列乘以值300来添加2个新列，如下所示：

^{pr2}$

如果我使用上面的代码，我会得到以下错误：

TypeError: can't multiply sequence by non-int of type 'float'

我该怎么纠正呢？在

Answer 1

首先尝试转换为float：

df['Modelled Volume(f3)'] = df['Modelled flow (cfs)'].astype(float)*300.00
df['Observed Volume(f3)'] = df['Observed Flow (cfs)'].astype(float)*300.00
print (df)
      Event  Modelled flow (cfs)  Observed Flow (cfs)  Modelled Volume(f3)  \
0  Event 01             0.861072             2.105263            258.32169   
1  Event 01             0.859609             2.383901            257.88261   
2  Event 01             0.874982             2.092879            262.49463   
3  Event 01             0.904507             2.119195            271.35216   
4  Event 01             0.926783             2.156347            278.03496   
5  Event 01             0.915608             1.883901            274.68249   

   Observed Volume(f3)  
0             631.5789  
1             715.1703  
2             627.8637  
3             635.7585  
4             646.9041  
5             565.1703  

如果第一个解决方案失败，请将带有参数errors='coerce'的列^{}转换为NaN：

^{pr2}$