用正则表达式和熊猫分隔字符串

Question

I have below content and I need to seperate third part as below with panda in python:

My string:

FA0003 -BL- FA0005-BL
FA0004-BL-FA0008-BL

My Expected:

FA0005
FA0008

Imagine I have a string like this in a column named A, the regex of below string for retrieving FA0003 is as below, but i dont now how to retrieve FA0005?

FA0003 -BL- FA0005-BL
df[A].str.extract(r'(\w+\s*)', expand=False)
FA0003

Answer 1

You can use

^(?:[^-]*-){2}\s*([^-]+)

See the regex demo

In Pandas, use it with your current code:

df[A].str.extract(r'^(?:[^-]*-){2}\s*([^-]+)', expand=False)

Details

• ^ - start of string
• (?:[^-]*-){2} - two occurrences of any chars other than - and then a -
• \\s* - zero or more whitespaces (this is used to trim the output)
• ([^-]+) - Capturing group 1 (the return value): one or more chars other than - .