On 6/28/07, Hamptonio <[EMAIL PROTECTED]> wrote:
> Interesting. I think I originally ripped mine off from one of [...]
Hi,
I've incorporated this into SAGE as a patch. The main things I did
were add more examples and delete part of the function which I
consider stupid. E.g., you wrote "flatten(GF(5)) does return [0,1,2,3,4]"
but in fact it doesn't -- it returns [1,2,3,4] -- since it removes all things
that evaluate to False because of this code:
if not new_list[index]:
new_list.pop(index)
continue
So I deleted that code, since I see no reason for it, and all the examples
work fine without it.
Comments?
William
[EMAIL PROTECTED]:~/d/sage/sage/misc$ hg export 5194
# HG changeset patch
# User William Stein <[EMAIL PROTECTED]>
# Date 1183076918 25200
# Node ID 25f23d18288895f46a6aaa2bd8ef147cde5e31f3
# Parent 65b460226d8173061face0c810fa6cffaf20dc08
Marshall Hampton's flatten command (suitably modified)
diff -r 65b460226d81 -r 25f23d182888 sage/misc/all.py
--- a/sage/misc/all.py Thu Jun 28 16:17:05 2007 -0700
+++ b/sage/misc/all.py Thu Jun 28 17:28:38 2007 -0700
@@ -6,6 +6,8 @@ from misc import (alarm, srange, xsrange
repr_lincomb, tmp_dir, tmp_filename,
DOT_SAGE, SAGE_ROOT, SAGE_URL, SAGE_DB, SAGE_TMP,
is_32_bit, is_64_bit, newton_method_sizes)
+
+from flatten import flatten
from remote_file import get_remote_file
diff -r 65b460226d81 -r 25f23d182888 sage/misc/flatten.py
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/sage/misc/flatten.py Thu Jun 28 17:28:38 2007 -0700
@@ -0,0 +1,42 @@
+def flatten(in_list, ltypes=(list, tuple)):
+ """
+ Flattens a nested list.
+
+ INPUT:
+ in_list -- a list or tuple
+ ltypes -- optional list of particular types to flatten
+
+ OUTPUT:
+ a flat list of the entries of in_list
+
+ EXAMPLES:
+ sage: flatten([[1,1],[1],2])
+ [1, 1, 1, 2]
+ sage: flatten([[1,2,3], (4,5), [[[1],[2]]]])
+ [1, 2, 3, 4, 5, 1, 2]
+
+ In the following example, the vector isn't flattened because
+ it is not given in the ltypes input.
+ sage: flatten((['Hi',2,vector(QQ,[1,2,3])],(4,5,6)))
+ ['Hi', 2, (1, 2, 3), 4, 5, 6]
+
+ We give the vector type and then even the vector gets flattened:
+ sage: flatten((['Hi',2,vector(QQ,[1,2,3])], (4,5,6)),
ltypes=(list, tuple,sage.modules.vector_rational_dense.Vector_rational_dense))
+ ['Hi', 2, 1, 2, 3, 4, 5, 6]
+
+ We flatten a finite field.
+ sage: flatten(GF(5))
+ [0, 1, 2, 3, 4]
+ sage: flatten([GF(5)])
+ [Finite Field of size 5]
+ sage: flatten([GF(5)], ltypes = (list, tuple,
sage.rings.finite_field.FiniteField_prime_modn))
+ [0, 1, 2, 3, 4]
+
+ """
+ index = 0
+ new_list = [x for x in in_list]
+ while index < len(new_list):
+ while isinstance(new_list[index], ltypes):
+ new_list[index : index + 1] = list(new_list[index])
+ index += 1
+ return new_list
William
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to sage-devel@googlegroups.com
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at http://groups.google.com/group/sage-devel
URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/
-~----------~----~----~----~------~----~------~--~---
