Presumption
------------------------------------------------------------------------
1. Lists are mutable sequences.
2. There is a subtlety when the sequence is being modified by the FOR
loop (this can only occur for mutable sequences, i.e. lists)
Preamble
=====================================================================
To pass by reference or by copy of - that is the question from hamlet.
("hamlet" - a community of people smaller than a village python3.4-linux64)
xlist = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
i = 0
for x in xlist:
print(xlist)
print("\txlist[%d] = %d" % (i, x))
if x%2 == 0 :
xlist.remove(x)
print(xlist, "\n\n")
i = i + 1
So, catch the output and help me, PLEASE, improve the answer:
Does it appropriate ALWAYS RE-evaluate the terms of the expression list
in FOR-scope on each iteration?
But if I want to pass ONCE a copy to FOR instead of a reference (as seen
from an output) and reduce unreasonable RE-evaluation, what I must to do
for that?
========================================================================
Assumption. Wind of changes.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Sometimes FOR-loop may do a global work. (depends on size of expression
list)
Sometimes on external DB. (just a joke)
So, what can FOR-loop do for You, depends what can You do for expression
list, which can be mutable far outside YOUR NICE LOGIC.
QUEST
************************************************************************
Your example of FOR-loop with a simple logic and sensitive information,
operated by means of external list-array and Your elaborative vision of
hacking possibilities through mutation of a list's terms.
TIA
RSVP
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