pandas extractall() is not extracting all cases given a regex?
问题 I have a nested list of strings which I would like to extract them the date. The date format is: Two numbers (from 01 to 12 ) hyphen tree letters (a valid month) hyphen two numbers, for example: 08-Jan—07 or 03-Oct—01 I tried to use the following regex: r'\d{2}(—|-)(?:Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)-\d{2,4}' Then I tested it as follows: import pandas as pd df = pd.DataFrame({'blobs':['6-Feb- 1 4 Facebook’s virtual-reality division created a 3-EBÚ7 11 network of 500 free demo