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author | Georg Brandl <georg@python.org> | 2008-03-06 07:22:09 (GMT) |
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committer | Georg Brandl <georg@python.org> | 2008-03-06 07:22:09 (GMT) |
commit | 26bab5f92a9ec67647a1893dfc497d822c1f62bd (patch) | |
tree | 72a872c475dda791676898a99ea95a78de0603ad | |
parent | 70992c3c83e2324677ad4fee73f372682f036c18 (diff) | |
download | cpython-26bab5f92a9ec67647a1893dfc497d822c1f62bd.zip cpython-26bab5f92a9ec67647a1893dfc497d822c1f62bd.tar.gz cpython-26bab5f92a9ec67647a1893dfc497d822c1f62bd.tar.bz2 |
Little clarification of assignments.
-rw-r--r-- | Doc/tutorial/classes.rst | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/Doc/tutorial/classes.rst b/Doc/tutorial/classes.rst index 7761095..2eb86e2 100644 --- a/Doc/tutorial/classes.rst +++ b/Doc/tutorial/classes.rst @@ -123,6 +123,8 @@ found outside of the innermost scope are read-only (an attempt to write to such a variable will simply create a *new* local variable in the innermost scope, leaving the identically named outer variable unchanged). +.. XXX mention nonlocal + Usually, the local scope references the local names of the (textually) current function. Outside functions, the local scope references the same namespace as the global scope: the module's namespace. Class definitions place yet another @@ -136,14 +138,15 @@ language definition is evolving towards static name resolution, at "compile" time, so don't rely on dynamic name resolution! (In fact, local variables are already determined statically.) -A special quirk of Python is that assignments always go into the innermost -scope. Assignments do not copy data --- they just bind names to objects. The -same is true for deletions: the statement ``del x`` removes the binding of ``x`` -from the namespace referenced by the local scope. In fact, all operations that -introduce new names use the local scope: in particular, import statements and -function definitions bind the module or function name in the local scope. (The -:keyword:`global` statement can be used to indicate that particular variables -live in the global scope.) +A special quirk of Python is that -- if no :keyword:`global` or +:keyword:`nonlocal` statement is in effect -- assignments to names always go +into the innermost scope. Assignments do not copy data --- they just bind names +to objects. The same is true for deletions: the statement ``del x`` removes the +binding of ``x`` from the namespace referenced by the local scope. In fact, all +operations that introduce new names use the local scope: in particular, import +statements and function definitions bind the module or function name in the +local scope. (The :keyword:`global` statement can be used to indicate that +particular variables live in the global scope.) .. _tut-firstclasses: |