entering a date programatically in python sql string

Question

this is my current query

cursor = connection.cursor()
cursor.execute('SELECT *'\
    'FROM students' \
    'WHERE numberofclasses > 4')
list = cursor.fetchall()

now I wish to add to the string:

1. that registrationdate was in the past month --> how do I calculate and add the result to the string
2. the name starts with 'l' --> how do i add name like '%l' into the above string

Note:

1. it's important for my question to keep the string format of '...'\ '...'\ and not write it in between ''' ... '''
2. this is an example for a much complicated query that must be executed this way and not through Django ORM platform.

Answer 1

Lets break it up in few questions:

1. How to determine 'past month' python date of the previous month
2. Format for your database depends on the backend your using Mysql: https://dev.mysql.com/doc/refman/5.1/en/date-and-time-literals.html Postgres: http://www.postgresql.org/docs/9.1/static/datatype-datetime.html
3. Entering the value in your string:

Your could concatenate a formatted date:

cursor.execute('SELECT *'\
    'FROM students' \
    'WHERE numberofclasses > 4' \
    'AND mydate > \'%s\'', [month_ago.isoformat()])

https://docs.python.org/2/library/datetime.html#datetime.date.isoformat

I do not understand your second question, for this seems to contain the answer already.