QST: About the meaning of `~` used in `dfs = dfs.loc[:, ~dfs.columns.str.contains('^Unnamed', na=False)]`.
### 

- [X] I have searched the [[pandas] tag](https://stackoverflow.com/questions/tagged/pandas) on StackOverflow for similar questions.

- [X] I have asked my usage related question on [StackOverflow](https://stackoverflow.com).


### Link to question on StackOverflow

https://stackoverflow.com/a/64335734

### Question about pandas

Currently, I'm using the following method to get rid of `Unnamed: 0` column in a pandas DataFrame according to the comments noted [here](https://stackoverflow.com/questions/36519086/how-to-get-rid-of-unnamed-0-column-in-a-pandas-dataframe/66704993#66704993) and [here](https://stackoverflow.com/questions/52297740/typeerror-bad-operand-type-for-unary-float):


```python
import pandas as pd

excel='2021-2022-1.xlsx'
dfs = pd.read_excel(excel)
dfs = dfs.loc[:, ~dfs.columns.str.contains('^Unnamed', na=False)]
```
But I am puzzled by the meaning of the `~` symbol used above. I try to find some relevant explanations by googling or digging into the source code of  pandas, but still got nothing. Any hints for this question will be greatly appreciated.

Regards,
HZ