Python: How to pass in only one variable into a lambda function?

Python: How to pass in only one variable into a lambda function?

Lambda expressions syntax in Python is:

lambda [list of arguments]: <expression>

In your code you do not have any arguments defined for your lambdas. You need to add an argument named line before the : character to make your code work:

lambda line: write_csv(m, line), lambda line: write_csv(u, line)

Python: How to pass in only one variable into a lambda function?