How do I check for multiple exceptions in Python?

DNASequence = "laksjfklsajdfklsajfklasjfklsad"

    while True:
        lMerLength = input("Please enter the length of the l-mers of the universal array :")
        try:
            if len(DNASequence) >= lMerLength > 0:
                break
        except SyntaxError:
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        #This is not working. How do I check for multiple exceptions in Python?
        except NameError:
            pass
        print "ERROR: Please check your input. You entered an invalid input."

Here is how you check for multiple exceptions.

try:

    ..............

except (SyntaxError, NameError, ...):

    ..............

finally:

    .............

The problem is, that input returns a string and you compare that string in your if to an int. And in python 2.x you should use raw_input instead of input:

DNASequence = "laksjfklsajdfklsajfklasjfklsad"
while True:
    try:
        lMerLength = int(raw_input("Please enter the length of the l-mers of the universal array :"))
    except ValueError:
        print "ERROR: Please check your input. You entered an invalid input."
        continue
    if len(DNASequence) >= lMerLength > 0:
        break
    print "ERROR: Please check your input. You entered an invalid input."