def cast(df, column: str, type: str, new_column=None):
new_column = new_column or column<EOL>df[new_column] = df[column].astype(type)<EOL>return df<EOL>
Convert column's type into type

---

### Parameters

*mandatory :*
- `column` (*str*): name of the column to convert
- `type` (*str*): output type. It can be :
    - `"int"` : integer type
    - `"float"` : general number type
    - `"str"` : text type

*optional :*
- `new_column` (*str*): name of the output column.
   By default the `column` arguments is modified.

---

### Example

**Input**

| Column 1 |  Column 2   |  Column 3  |
|:-------:|:--------:|:--------:|
|  'one'  |  '2014'  |   30.0   |
|  'two'  |  2015.0  |    '1'   |
|   3.1   |   2016   |    450   |

```cson
postprocess: [
  cast:
    column: 'Column 1'
    type: 'str'
  cast:
    column: 'Column 2'
    type: 'int'
  cast:
    column: 'Column 3'
    type: 'float'
]
```

**Output**

| Column 1 |  Column 2  |  Column 3  |
|:-------:|:------:|:--------:|
|  'one'  |  2014  |   30.0   |
|  'two'  |  2015  |    1.0   |
|  '3.1'  |  2016  |  450.0   |