Question: **Here is a column of my dataframe.**

[![enter image description here](https://i.stack.imgur.com/OkG4G.png)](https://i.stack.imgur.com/OkG4G.png)

I want to select for example for the first image 28g and delete (1 ONZ). **how can I do ?**

Answer: 
Use `replace`:

```
df.serving_size.str.replace('\(.*','')

0     NaN
1    28g 
2    28g 
3    28g
4    35g
5    52g
Name: serving_size, dtype: object

```
You can extract everything outside of the parentheses:

```
# original df
>>> df
      serving_size
0              NaN
1     28 g (1 ONZ)
2  28 g (0.25 cup)

>>> df.serving_size.str.extract('(.*)\(.*\)')
0      NaN
1    28 g 
2    28 g 
Name: serving_size, dtype: object

```