Is '[' a function or an operator or an language feature?
in [Python]
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From: Peng Yu on 16 Jul 2010 13:01 I mean to get the man page for '[' like in the following code. x=[1,2,3] But help('[') doesn't seem to give the above usage. ########### Mutable Sequence Types ********************** List objects support additional operations that allow in-place modification of the object. Other mutable sequence types (when added to the language) should also support these operations. Strings and tuples are immutable sequence types: such objects cannot be modified once created. The following operations are defined on mutable sequence types (where *x* is an arbitrary object): .... ########## I then checked help('LISTLITERALS'), which gives some description that is available from the language reference. So '[' in "x=[1,2,3]" is considered as a language feature rather than a function or an operator? ############ List displays ************* A list display is a possibly empty series of expressions enclosed in square brackets: list_display ::= "[" [expression_list | list_comprehension] "]" list_comprehension ::= expression list_for list_for ::= "for" target_list "in" old_expression_list [list_iter] old_expression_list ::= old_expression [("," old_expression)+ [","]] list_iter ::= list_for | list_if list_if ::= "if" old_expression [list_iter] ...... ########### -- Regards, Peng
From: Robert Kern on 16 Jul 2010 13:41 On 7/16/10 12:01 PM, Peng Yu wrote: > I then checked help('LISTLITERALS'), which gives some description that > is available from the language reference. So '[' in "x=[1,2,3]" is > considered as a language feature rather than a function or an > operator? Yes. It is part of the list literal syntax of the Python language. -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco
From: Terry Reedy on 16 Jul 2010 18:42 On 7/16/2010 1:01 PM, Peng Yu wrote: > I mean to get the man page for '[' like in the following code. > > x=[1,2,3] You might find my Python symbol glossary useful. https://code.google.com/p/xploro/downloads/detail?name=PySymbols.html
From: Peng Yu on 16 Jul 2010 21:42 On Fri, Jul 16, 2010 at 5:42 PM, Terry Reedy <tjreedy(a)udel.edu> wrote: > On 7/16/2010 1:01 PM, Peng Yu wrote: >> >> I mean to get the man page for '[' like in the following code. >> >> x=[1,2,3] > > You might find my Python symbol glossary useful. > https://code.google.com/p/xploro/downloads/detail?name=PySymbols.html This is for Python 3. Is there one for Python 2.x? -- Regards, Peng
From: MRAB on 16 Jul 2010 22:08
Peng Yu wrote: > On Fri, Jul 16, 2010 at 5:42 PM, Terry Reedy <tjreedy(a)udel.edu> wrote: >> On 7/16/2010 1:01 PM, Peng Yu wrote: >>> I mean to get the man page for '[' like in the following code. >>> >>> x=[1,2,3] >> You might find my Python symbol glossary useful. >> https://code.google.com/p/xploro/downloads/detail?name=PySymbols.html > > This is for Python 3. Is there one for Python 2.x? > Is anyone /still/ using Python 2.x? ;-) |