我无法理解如何更正此问题
c_df
lotsize strike_lots amt_cvr
0 75.0 1.0 1.0
1 2500.0 N 943845
2 100.0 N 742350
3 600.0 2.0 2.0
4 8000.0 N 585214
5 3500.0 N 838704
6 6000.0 2.0 2.0
7 4000.0 N 709020
8 1500.0 N 263610
c_df.loc[c_df['strike_lots'] != 'N', 'amt_cvr'] = float(c_df['strike_lots'])*c_df['lotsize']
我检查了dtypes
lotsize float64
strike_lots object
amt_cvr object
dtype: object
我假设的问题是 strike_lots 的 dtype，我不想更改它，因为我想保留 N 值。
Traceback (most recent call last):
File "/media/sid1/sid/lib/python3.6/site-packages/pandas/core/ops.py", line 1012, in na_op
result = expressions.evaluate(op, str_rep, x, y, **eval_kwargs)
File "/media/sid1/sid/lib/python3.6/site-packages/pandas/core/computation/expressions.py", line 205, in evaluate
return _evaluate(op, op_str, a, b, **eval_kwargs)
File "/media/sid1/sid/lib/python3.6/site-packages/pandas/core/computation/expressions.py", line 65, in _evaluate_standard
return op(a, b)
TypeError: can't multiply sequence by non-int of type 'float'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/media/sid1/sid/lib/python3.6/site-packages/pandas/core/ops.py", line 1033, in safe_na_op
return na_op(lvalues, rvalues)
File "/media/sid1/sid/lib/python3.6/site-packages/pandas/core/ops.py", line 1018, in na_op
result[mask] = op(x[mask], com._values_from_object(y[mask]))
TypeError: can't multiply sequence by non-int of type 'float'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "<input>", line 1, in <module>
File "/media/sid1/sid/lib/python3.6/site-packages/pandas/core/ops.py", line 1069, in wrapper
result = safe_na_op(lvalues, rvalues)
File "/media/sid1/sid/lib/python3.6/site-packages/pandas/core/ops.py", line 1037, in safe_na_op
lambda x: op(x, rvalues))
File "pandas/_libs/algos_common_helper.pxi", line 1212, in pandas._libs.algos.arrmap_object
File "/media/sid1/sid/lib/python3.6/site-packages/pandas/core/ops.py", line 1037, in <lambda>
lambda x: op(x, rvalues))
TypeError: ufunc 'multiply' did not contain a loop with signature matching types dtype('<U32') dtype('<U32') dtype('<U32')
预期输出
c_df
lotsize strike_lots amt_cvr
0 75.0 1.0 75.0 #this value changes
1 2500.0 N 943845
2 100.0 N 742350
3 600.0 2.0 1200.0 #This value changes
4 8000.0 N 585214
5 3500.0 N 838704
6 6000.0 2.0 12000.0 #This value changes
7 4000.0 N 709020
8 1500.0 N 263610
提前致谢。
请您参考如下方法:
您可以使用to_numeric 和fillna
df['amt_cvr'] = (df['lotsize']*pd.to_numeric(df['strike_lots'],errors='coerce')).fillna(df['amt_cvr'])
lotsize strike_lots amt_cvr
0 75.0 1.0 75.0
1 2500.0 N 943845.0
2 100.0 N 742350.0
3 600.0 2.0 1200.0
4 8000.0 N 585214.0
5 3500.0 N 838704.0
6 6000.0 2.0 12000.0
7 4000.0 N 709020.0
8 1500.0 N 263610.0
pd.to_numeric(df['strike_lots'],errors='coerce') 会将非数值转换为 NaN。因此，当您将它与数字列相乘时，其输出也将是 NaN。
然后我们可以使用 fillna 用实际的 amt_cvr 填充空值。希望能帮助到你。
