Add parenthesis on print statements so that code works in python3 too!

``` python
print('yo')
print(dataframe)
print(dataframe)
print(inputX)
print(inputY)
    print("Training step:", '%04d' % (i), "cost=", "{:.9f}".format(cc)) #, \"W=", sess.run(W), "b=", sess.run(b)    
print("Optimization Finished!")
print(training_cost)
```
