在Python中使用sys.stdout.write嵌入变量

Question

I can embed variables using the print statement in python in this way

i=10
print "Value is %s" % (i)

Output

 Value is 10 

but doing this

i=10
sys.stdout.write ("Value is %s") % (i)

gives me the following error

 TypeError: unsupported operand type(s) for %: 'NoneType' and 'int' 

Can I embed variables using sys.stdout.write instead of print?

Answer 1

You got the parentheses wrong. Should be

i=10
sys.stdout.write("Value is %s" % i)

The % operator takes a string and a tuple (or a single object) as arguments. You tried to apply the operator to the return value of sys.stdout.write() , which is None. You need to apply it to the string before it is passed to sys.stdout.write() .