6.6 The print statement
Description: The print statement
Keywords: ref

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6.6 The `print` statement

  `print_stmt` | ::= | `"print" ( [expression ("," expression)* [","]]`
  |  | `| ">`>`" expression [("," expression)+ [","]] )`

  Download entire grammar as text.

`print` evaluates each expression in turn and writes the resulting object to standard output (see below). If an object is not a string, it is first converted to a string using the rules for string conversions. The (resulting or original) string is then written. A space is written before each object is (converted and) written, unless the output system believes it is positioned at the beginning of a line. This is the case (1) when no characters have yet been written to standard output, (2) when the last character written to standard output is "`\n`", or (3) when the last write operation on standard output was not a `print` statement. (In some cases it may be functional to write an empty string to standard output for this reason.) Note: Objects which act like file objects but which are not the built-in file objects often do not properly emulate this aspect of the file object's behavior, so it is best not to rely on this.

A "`\n`" character is written at the end, unless the `print` statement ends with a comma. This is the only action if the statement contains just the keyword `print`.

Standard output is defined as the file object named `stdout` in the built-in module `sys`. If no such object exists, or if it does not have a `write()` method, a `RuntimeError` exception is raised.

`print` also has an extended form, defined by the second portion of the syntax described above. This form is sometimes referred to as ```print` chevron.'' In this form, the first expression after the `>``>` must evaluate to a ``file-like'' object, specifically an object that has a `write()` method as described above. With this extended form, the subsequent expressions are printed to this file object. If the first expression evaluates to `None`, then `sys.stdout` is used as the file for output.