Here's the code to find the rows where the sum of all rows of the fund_columns in banking are equal to the inv_amount column, store the values of banking with consistent inv_amount in `consistent_inv`, and those with inconsistent ones in `inconsistent_inv`:
```python
# Store fund columns to sum against
fund_columns = ['fund_A', 'fund_B', 'fund_C', 'fund_D']
# Find rows where fund_columns row sum == inv_amount
inv_equ = banking[fund_columns].sum(axis=1) == banking['inv_amount']
# Store consistent and inconsistent data
consistent_inv = banking[inv_equ]
inconsistent_inv = banking[~inv_equ]
# Print number of inconsistent investments
print("Number of inconsistent investments: ", inconsistent_inv.shape[0])
```
In this code, we first define a list `fund_columns` that contains the names of the columns we want to sum against.
We then create a boolean mask `inv_equ` that checks if the sum of each row of the `fund_columns` is equal to the `inv_amount` column.
We use this boolean mask to filter the `banking` DataFrame into two separate DataFrames: `consistent_inv` and `inconsistent_inv`. The `consistent_inv` DataFrame contains the rows where the sum of the `fund_columns` is equal to the `inv_amount` column, while the `inconsistent_inv` DataFrame contains the rows where they are not equal.
Finally, we print the number of inconsistent investments using the `shape` attribute of the `inconsistent_inv` DataFrame.