Why Does Python 2.x Throw a 'SyntaxError: Missing parentheses in call to 'print'' When Using the 'end' Keyword Argument?

Handling SyntaxError with Print and End Keyword Argument

When attempting to execute the following code:

if Verbose:
   print("Building internal Index for %d tile(s) ...", end=' ')

an error occurs: "SyntaxError: Missing parentheses in call to 'print'". This is because the keyword argument end is not supported in Python 2.x.

Understanding the Difference

In Python 2.x, print functions as a statement. Hence, the above code is interpreted as a tuple-wrapped call to print, with the final argument being a string literal. However, string literals do not support keyword arguments, leading to the error.

Solution for Python 2.x

In Python 2.x, employ one of the following methods to end a line with a space:

• Add a final comma to the print statement:

  print "Building internal Index for %d tile(s) ...",

• Use the sys.stdout module directly for greater control over output:

  import sys
  sys.stdout.write("Building internal Index for %d tile(s) ... ")

Enabling End Keyword Argument in Python 2.x

In recent versions of Python 2.x (2.5 and later), the __future__ module allows for the activation of the print function as a function by importing print_function. However, this method may not be compatible with older Python 2.x versions.

Transition to Python 3.x

In Python 3.x, print behaves as a function, enabling the use of keyword arguments such as end. Therefore, the original code should execute correctly in Python 3.x without any modifications.

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