What is the difference in:
some_list1 = []
some_list1.append("something")
and
some_list2 = []
some_list2 += ["something"]
I hope this hasn't been already posted. If so just point me in that direction :)
Thanks for your help.
EDIT
I've ... |
Is there a reason being list.append evaluating to false? Or is it just the C convention of returning 0 when successful that comes into play?
>>> u=[]
>>> not u.append(6)
True
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L = ['abc', 'ADB', 'aBe']
L[len(L):]=['a1', 'a2'] # append items at the end...
L[-1:]=['a3', 'a4'] # append more items at the end...
... works, but 'a2' is missing in the output:
['abc', 'ADB', 'aBe', 'append', ...
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I'm trying to write a function that reads files from a "deferred" directory which contains files that contain lists. Here's what the files in the deferred folder contain:
'173378981', '45000', '343434', '3453453', ...
|
I was writing this little piece of code as an exercise in object-oriented programming.
Here I'm trying to define a house as a list of rooms and each room as a list ... |
I'm going through a whole bunch of tuples with a many-to-many correlation, and I want to make a dictionary where each b of (a,b) has a list of all the a's ... |
Here is my code -
cumulative_nodes_found_list = []
cumulative_nodes_found_total_list = []
no_of_runs = 10
count = 0
while count < no_of_runs:
#My program code
print 'cumulative_nodes_found_list - ' + str(cumulative_nodes_found_list)
cumulative_nodes_found_total_list.insert(count,cumulative_nodes_found_list)
print 'cumulative_nodes_found_total_list - ' ...
|
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I've got this code:
def __parse(self):
for line in self.lines:
r = Record(line)
...
|
I have a text file with a few 1000 lines of text in it. A sample is given below:
person1
person2
person3
person4
have paid
---------
person5
person6
person7
person9
person10
person11
have paid
---------
Each line starts with either "p" or "h" or "-". When ... |
I have a list, let's say, a=[[1,2],[3,4],[5,6]]
I want to add to each item in a the char 'a'.
When I use:
a=[x.append('a') for x in a]
it returns [None,None,None].
But if I ... |
Having a list like this:
['foo','spam','bar']
is it possible, using list comprehension, to obtain this list as result?
['foo','ok.foo', 'spam', 'ok.spam', 'bar', 'ok.bar']
|
if i start off with :
a=[1,2,4]
and i want the result to be
a=[1,3,2,4]
how do i do this append?
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Does this leak?:
static PyObject* foo(PyObject* self, PyObject* args){
PyObect* list = PyList_New(0);
for(int i = 0; i < 100; i++)
...
|
When I execute (I'm using the interactive shell) these statements I get this:
L=[1,2,3]
K=L
L.append(4)
L
[1,2,3,4]
K
[1,2,3,4]
But when I do exactly the same thing replacing L.append(4) with L=L+[4]
I get:
L
[1,2,3,4]
K
[1,2,3]
Is this some sort of reference thing? ... |
In Python Shell, I entered:
aList = ['a', 'b', 'c', 'd']
for i in aList:
print(i)
and got
a
b
c ...
|
i have a list of a list:
b=[[1,2,3],[4,5,6],[7,8,9]]
i have a list:
row = [1,2,3]
how do i append to b only row[0] and '3847' and row[2] such that b will equal:
b=[[1,2,3],[4,5,6],[7,8,9],[1,3847,3]]
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I have the following code:
myList.append(node)
Can anyone suggest possible reasons for that?
Thanks!
|
This seems like something Python would have a shortcut for. I want to append an item to a list N times, effectively doing this:
l = []
x = 0
for i in range(100):
...
|
How do you append the elements of a set to a list in Python in the most succinct way?
>>> a = [1,2]
>>> b = set([3,4])
>>> a.append(list(b))
>>> a
[1, 2, [3, 4]]
But what ... |
I have the following question for homework
Define a function append lists that
takes a list of lists and returns a
new list containing the sublist
values. ... |
Need Help As soon as possible .
Thank you in advance
|
I seem to have a problem with my maze generating program made in Python. I'm trying to randomly create a path that branches out at select points, with the points getting ... |
Today I spent about 20 minutes trying to figure out why
this worked as expected:
users_stories_dict[a] = s + [b]
but this would have a None value:
users_stories_dict[a] = s.append(b)
Anyone know why ... |
Possible Duplicate:
Python: Adding element to list while iterating
This doesn't seem to work, but I am not sure why:
for n in poss:
...
|
I create a list of lists and want to append items to the individual lists, but when I try to append to one of the lists (a[0].append(2)), the item gets added ... |
Is there a straightforward way to get the index of an item I just appended to a list? I need to keep track of the last added item.
I came up with ... |
Basically there seems to be a problem when a list of lists is made by appending a list to another list using list.append(). The problem is that the entire column is ... |
I want to attach a list to itself and I thought this would work:
x = [1,2]
y = x.extend(x)
print y
I wanted to get back [1,2,1,2] but all I get back is the ... |
I'm trying to append a new float element to a list within another list, for example:
list = [[]]*2
list[1].append(2.5)
And I get the following:
print list
[[2.5], [2.5]]
When I'd like to get:
[[], [2.5]]
How can I ... |
Okay, I have a list that looks like this
OldList = [1000, 2000, 3000, 4000, 5000]
And I want to run all members of that list through a function called ListMultiply, like so
NewList ...
|
I have a list called teams which contains two objects, these are objects of the same class and they both have a "members" list. I am appending to these lists individually. ... |
How can i modify this code to make 3 lists with 5 elements in each instead of as it is now; 3 lists with 5/10/15 elements?
import random
y = []
def autoSolve():
...
|
How can I create a list in a function, append to it, and then pass another value into the function to append to the list.
For example:
def another_function():
y ...
|
Don't really know how to formulate the question...
Suppose I do the following:
>>> l = [[]]*2
>>> l
[[], []]
...
|
I am trying to parse a log file with threadids in every like. There could be any number of threads that can be configured. All threads write to the same log ... |
I've encountered what I think is a strange behavior in Python, and I'd like somebody to explain it if possible.
I've created an empty 2D list
listy = [[]]*3
print listy
[[], [], []]
The following ... |
Possible Duplicate:
“Least Astonishment” in Python: The Mutable Default Argument
This is very odd, an optional list parameter in Python is persistent between function calls when ... |
code
a = "??" #korean language
a_list = []
a_list.append({'key': a})
print a_list
result
[{'key': u'"\ud55c\uae00"'}]
I dont want to convert unicode.
How can I stay in korean language
I wish to print like this
[{'key': ...
|
Working in python 2.7.
I have two lists (simplified to make explanations clearer).
T = [[1,0], [1,0], [0,5], [3, -1]]
B = [[1], [3], [2], [2]]
I would like to append the second list (B) ... |
I have created an object type.. and after initilializing I am pushing that into a list.
but for some reason the behavior is not as expected.
let me put in the sample code.. ... |
Why does the following code give 'None'? How can I resolve this?
def f1(list1):
f2(list1.append(2))
def f2(list1):
print(list1)
f1([1])
What also doesn't work:
def f1(list1):
arg1 = ...
|
I have a nested list that looks like this:
mylist = [['A;B', 'C'], ['D;E', 'F']]
I'd like to have it in the following form:
[['A', 'B', 'C'], ['D', 'E', 'F']]
Figured I'd write a simple ... |
Ok, so lets say I have a .csv file called flags.csv, with the following data (Column 1)- (Column 2) Country- Colour Australia- Red Australia- Red Australia- Red America - Red UK - Red Japan- Red China - Red Australia- White America - White UK - White Japan - White Australia -Blue America - Blue UK - Blue China - Yellow I ... |
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>>> cands = [] >>> for x in range(1, 10000): ... if x % 2 > 0: ... cands.append(x) ... else: ... None ... print cands File ... |
having __init__() append self to a list by metulburr Wed Dec 07, 2011 9:40 am i have been trying different methods to append self to a list. I want all the instances 'name's to be in a list but 1) can't figure out how to even do it and 2) how to call up that list if it is in ... |
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This seems like a trivial problem but I can't find a fix. I have a list of lists and I want to append/update a specific list each time I loop. Currently, whenever I append to one list, all of the lists get appended to. My code looks something like the following: list = [[]]*length for i in loop: index = someComputedValue ... |
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I have a .csv file that contains stock candle data (date, time, open, high, low, close, volume) and I'm trying to nest lists by candle and then by day and then by week. So pretty much, I want each day list to consist of lists of each candle and each week list to consist of lists of each day. I just ... |
counter = 0 my_list = [] while counter < 6100900: x = random.randrange(0, 101, 2) y = x + 1 #print x, "this is x" #print y, "this is y" my_list.append(y) counter = counter + 1 |
Hello all, I have a list of numbers between 0 and 100, ie: [98, 75, 87, 90, 92, 81, 90, 98, 93, 86, 79, 91, 74] I need to append numbers greater than or equal to 90 to another list only if there is more than one consecutive number above 90. So my new list would be: [90, 92, 90, 98, ... |
pybee: Yeah I know I have to use append and the index number of the list in somekind of for loop. But I can't really get it to work as I want. Is a while loop maybe better in this case. First count the index number with howmany)= len(list) and then append while howmany > 0 and then add a howmany ... |
import urllib def file_to_list(reader): open_file = urllib.urlopen(reader) newL = [] for line in open_file: data = line.split() for data in line: ... |
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Zyzle's right. If you want to append a copy of the current list, you can (often) do this: Code: Select all >>> l = [1, 2, 3, 4, 5] >>> l [1, 2, 3, 4, 5] >>> l.append(l[:]) # Uses slice notation[1] >>> l [1, 2, 3, 4, 5, [1, 2, 3, 4, 5]] Copying a variable is -- to me ... |
xs = [line[:-1] for line in open('./header_template.py')] >>> len(xs) 14 >>> for l in xs: ... print ">%s<" % l ... >#!/usr/local/bin/python< ># < ># Created 2007// by Bill Wood.< >< ># import sys, os, tempfile< >< >###=====================================================================< >### Stand-alone driver. Currently does nothing.< >< >def main():< > print "Do nothing. Just exit."< >< ... |
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Traceback (most recent call last): File "", line 1, in File "", line 2, in append File "/usr/lib/python2.6/multiprocessing/managers.py", line 740, in _callmethod raise convert_to_error(kind, result) multiprocessing.managers.RemoteError: --------------------------------------------------------------------------- Traceback (most recent call last): File "/usr/lib/python2.6/multiprocessing/managers.py", line 214, in serve_client request = recv() AttributeError: 'module' object ... |