删除 pandas dataframe 中第一个空格之后的所有内容

Question

Here is the dataframe:

     State  RegionName            
0    NY     New York             
1    CA     Los Angeles      
2    IL     Chicago 865         
3    PA     Philadelphia Wrin   
4    AZ     Phoenix City 

I want the output to look like this:

     State   RegionName           
0    NY      New             
1    CA      Los         
2    IL      Chicago            
3    PA      Philadelphia 
4    AZ      Phoenix     

How to do it without using for loops??

Answer 1

Use Series.str.split with select first values by indexing:

print (df['RegionName'].str.split())
0             [New, York]
1          [Los, Angeles]
2          [Chicago, 865]
3    [Philadelphia, Wrin]
4         [Phoenix, City]
Name: RegionName, dtype: object

df['RegionName'] = df['RegionName'].str.split().str[0]
print (df)
  State    RegionName
0    NY           New
1    CA           Los
2    IL       Chicago
3    PA  Philadelphia
4    AZ       Phoeni

Answer 2

Here's an alternative using pd.Series.str.extract

df['RegionName'] = df['RegionName'].str.extract(r'(.*)\s')

But my first instinct would be to use what @jezrael mentioned.

Regex demo

Answer 3

You could also str.extract the start of the string but exclude space ^[^\s]+ using regex

df['RegionName']=df['RegionName'].str.extract('(^[^\s]+)')

Answer 4

You can replace extra words by '' using str.replace

df["RegionName"] = df.RegionName.str.replace('\s.*','')
df
     RegionName state
0           New    NY
1           Los    CA
2       Chicago    IL
3  Philadelphia    PA
4       Phoenix    AZ