从Pandas数据帧中的字符串中删除单个字母

Question

I have a DataFrame where a column is filled with strings. I want to remove any appearance of single letters from the column. So far, I have tried:

df['STRI'] = df['STRI'].map(lambda x: " ".join(x.split() if len(x) >1)

I wish to input ABCD X WYZ and get ABCD WYZ .

Answer 1

You can use str.replace and regex. The pattern \\b\\w\\b will replace any single word character with a word boundary. See working example below:

Example using series:

s = pd.Series(['Katherine','Katherine and Bob','Katherine I','Katherine', 'Robert', 'Anne', 'Fred', 'Susan', 'other'])

   s.str.replace(r'\b\w\b','').str.replace(r'\s+', ' ')

0            Katherine
1    Katherine and Bob
2            Katherine
3            Katherine
4               Robert
5                 Anne
6                 Fred
7                Susan
8                other
dtype: object

Another example with your test data:

    s = pd.Series(['ABCD','X','WYZ'])

0    ABCD
1       X
2     WYZ
dtype: object

s.str.replace(r'\b\w\b','').str.replace(r'\s+', ' ')

0    ABCD
1        
2     WYZ
dtype: object

With your data it is:

df['STRI'].str.replace(r'\b\w\b','').str.replace(r'\s+', ' ')

Answer 2

Try this:

df['STRI'] = npi['STRI'].str.replace(r'\b\w\b', '').str.replace(r'\s+', ' ')

---

Eg:

import pandas as pd

df = pd.DataFrame(data=['X ABCD X X WEB X'], columns=['c1'])
print df, '\n'
df.c1 = df.c1.str.replace(r'\b\w\b', '').str.replace(r'\s+', ' ')
print df

Output:

                 c1
0  X ABCD X X WEB X 

           c1
0   ABCD WEB 

Answer 3

list comprehension

[
    ' '.join([i for i in s.split() if len(i) > 1])
    for s in npi.STRI.values.tolist()
]

str.split

s = npi.STRI.str.split(expand=True).stack()
s[s.str.len() > 1].groupby(level=0).apply(' '.join)