import re
from itertools import groupby

string = "section_category_name = 'computer and equipment expense' and date >= 2015-01-01 and date <= 2015-03-31"

lexer = re.compile(r"'[^']*'|[^\s']+")
grouping = groupby(lexer.findall(string), lambda x: x == 'and')
results = [ ' '.join(g) for k, g in grouping if not k ]

print results