python - 如何将搜索到的字符串插入到熊猫的新行中

Question

我有一个包含一组特定数据的 Excel 示例：

Sno String
1   ram has a ball
2   karan has a ball
3   raj has a ball
4   seema has a ball
5   raj has a ball   raj

从上面的 df 我想提取特定的名称集并将它们写入新列

Sno String           names  count
1   ram has a ball   ram    1
2   karan has a ball karan  2
3   raj has a ball   raj    3
4   seema has a ball
5   raj has a ball   raj    4

我正在使用的代码：

import pandas as pd
import re
df = pd.read_excel (r'<path>')

array = {'ram','karan','raj'}
count = 0
for index, row in df.iterrows():
   sql = row["string"]
   for i in array:
       str = re.findall(i,sql)
       if str:
           count = count + 1
       else :
           continue
       df["name"] = pd.Series(str)
       df["count"] = pd.Series(count)
       
path_to_file = r'<path>'
df.to_excel(path_to_file)  

代码正在运行，但它只迭代一行而不是为每次迭代写入行值

我得到的输出：

Sno String           names  count
1   ram has a ball   ram    1
2   karan has a ball 
3   raj has a ball   
4   seema has a ball
5   raj has a ball   

谁能帮我解决我的问题？

标签： pythonpandas

Answer 1

我们可以str.findall从pandas

df['names'] = df.String.str.findall('|'.join(array)).str[0]
df['cnt'] = df.names.notna().cumsum().mask(df.names.isna())
df
Out[176]: 
              String  names  cnt
0     ram has a ball    ram  1.0
1   karan has a ball  karan  2.0
2     raj has a ball    raj  3.0
3   seema has a ball    NaN  NaN
4  raj has a ball       raj  4.0