Question: I want to delete every row that has cell with `?` value in it.
I do not know where `?` value is (i do not know name of the column).
Any idea how to do this:

```
df = pd.DataFrame({'A': [1,4,6,"?",3],
                   'B': ["?",3,5,1,4],
                   'C': [13,5,61,5, "?"]})

```

Desired output:

```
   A  B   C
0  4  3   5
1  6  5  61

```

Answer: 
You can use below code:

```
df=df.replace('?',np.nan)
df.dropna(inplace=True)
    A   B   C
1   4.0 3.0 5.0
2   6.0 5.0 61.0

```

For more information please see [`https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.dropna.html`](https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.dropna.html)
One line version : 

```
result = df.replace('?', pd.np.nan).dropna()

```