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call: `primary` "(" [`argument_list` [","]
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: | `expression` `genexpr_for`] ")"
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argument_list: `positional_arguments` ["," `keyword_arguments`]
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: ["," "*" `expression`]
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: ["," "**" `expression`]
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: ["," "*" `expression`] ["," `keyword_arguments`]
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: ["," "**" `expression`]
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: | `keyword_arguments` ["," "*" `expression`]
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: ["," "**" `expression`]
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: | "*" `expression` ["," "**" `expression`]
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: ["," "**" `expression`]
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: | "*" `expression` ["," "*" `expression`] ["," "**" `expression`]
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: | "**" `expression`
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positional_arguments: `expression` ("," `expression`)*
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keyword_arguments: `keyword_item` ("," `keyword_item`)*
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If the syntax ``*expression`` appears in the function call, ``expression`` must
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evaluate to a sequence. Elements from this sequence are treated as if they were
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additional positional arguments; if there are positional arguments *x1*,...,*xN*
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, and ``expression`` evaluates to a sequence *y1*,...,*yM*, this is equivalent
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to a call with M+N positional arguments *x1*,...,*xN*,*y1*,...,*yM*.
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additional positional arguments; if there are positional arguments *x1*,...,
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*xN*, and ``expression`` evaluates to a sequence *y1*, ..., *yM*, this is
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equivalent to a call with M+N positional arguments *x1*, ..., *xN*, *y1*, ...,
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A consequence of this is that although the ``*expression`` syntax appears
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*after* any keyword arguments, it is processed *before* the keyword arguments
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A consequence of this is that although the ``*expression`` syntax may appear
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*after* some keyword arguments, it is processed *before* the keyword arguments
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(and the ``**expression`` argument, if any -- see below). So::
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The operators :keyword:`is` and :keyword:`is not` test for object identity: ``x
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is y`` is true if and only if *x* and *y* are the same object. ``x is not y``
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yields the inverse truth value.
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yields the inverse truth value. [#]_
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(expr1, expr2, expr3, expr4)
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{expr1: expr2, expr3: expr4}
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expr1 + expr2 * (expr3 - expr4)
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func(expr1, expr2, *expr3, **expr4)
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expr1(expr2, expr3, *expr4, **expr5)
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expr3, expr4 = expr1, expr2
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+-----------------------------------------------+-------------------------------------+
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| ``**`` | Exponentiation |
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+-----------------------------------------------+-------------------------------------+
1302
| ``x.attribute`` | Attribute reference |
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+-----------------------------------------------+-------------------------------------+
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| ``x[index]`` | Subscription |
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+-----------------------------------------------+-------------------------------------+
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| ``x[index:index]`` | Slicing |
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+-----------------------------------------------+-------------------------------------+
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| ``f(arguments...)`` | Function call |
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| ``x(arguments...)`` | Call |
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+-----------------------------------------------+-------------------------------------+
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| ``x.attribute`` | Attribute reference |
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+-----------------------------------------------+-------------------------------------+
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| ``(expressions...)`` | Binding or tuple display |
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+-----------------------------------------------+-------------------------------------+
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only, but this caused surprises because people expected to be able to test a
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dictionary for emptiness by comparing it to ``{}``.
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.. [#] Due to automatic garbage-collection, free lists, and the dynamic nature of
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descriptors, you may notice seemingly unusual behaviour in certain uses of
1358
the :keyword:`is` operator, like those involving comparisons between instance
1359
methods, or constants. Check their documentation for more info.
added
removed
Doc/reference/expressions.rst
