def satisfiesF( L) :
"""
Assumes L is a list of strings
Assume function f is already defined for you and it maps a string to a Boolean
Mutates L such that it contains all of the strings, s, originally in L such
that f(s) returns True, and no other elements
Returns the length of L after mutation
"""
for e in L:
if not f( e) :
alis.remove ( e)
print len ( L)
print L
def f( x) :
return 'a' in x
satisfiesF( [ 'ava' , 'nlki' , 'qorqorj' , 'jaja' ] )
satisfiesF( [ ] )
satisfiesF( [ '' , 'fafs' ] )
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