To handle this situation, you could opt for 4 options:

1. use single quotation inside a double quotation string (as Farid suggested)
e.g.  "Shipper's Company".
2. use multi line string 
e.g. """ Pickup Time,Shippers Company,Shippers Name,Shippers Phone No.,Shippers Address 1,Shippers Address 2,Shippers Postal Code,Consignees Company,Consignees Name,Consignees Phone No.,Consignees Address 1,Consignees Address 2,Consignees Postal Code,Comments\n"""
3. use escape character
e.g. 'Shipper\'s Company'
4. use of raw string 
e.g. r"Shipper's company"    # mostly used in matching expression of regular expression at python