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Sort list of strings numerically and filter duplicates?

Given a list of strings in the following format:
[
"464782,-100,4,3,1,100,0,0"
"465042,-166.666666666667,4,3,1,100,0,0",
"465825,-250.000000000001,4,3,1,100,0,0",
"466868,-166.666666666667,4,3,1,100,0,0",
"467390,-200.000000000001,4,3,1,100,0,0",
"469999,-100,4,3,1,100,0,0",
"470260,-166.666666666667,4,3,1,100,0,0",
"474173,-100,4,3,1,100,0,0",
"474434,-166.666666666667,4,3,1,100,0,0",
"481477,-100,4,3,1,100,0,1",
"531564,259.011439671919,4,3,1,60,1,0",
"24369,-333.333333333335,4,3,1,100,0,0",
"21082,410.958904109589,4,3,1,60,1,0",
"21082,-250,4,3,1,100,0,0",
"22725,-142.857142857143,4,3,1,100,0,0",
"23547,-166.666666666667,4,3,1,100,0,0",
"24369,-333.333333333335,4,3,1,100,0,0",
"27657,-200.000000000001,4,3,1,100,0,0",
"29301,-142.857142857143,4,3,1,100,0,0",
"30123,-166.666666666667,4,3,1,100,0,0",
"30945,-250,4,3,1,100,0,0",
"32588,-166.666666666667,4,3,1,100,0,0",
"34232,-250,4,3,1,100,0,0",
"35876,-142.857142857143,4,3,1,100,0,0",
"36698,-166.666666666667,4,3,1,100,0,0",
"37520,-250,4,3,1,100,0,0",
"42451,-142.857142857143,4,3,1,100,0,0",
"43273,-166.666666666667,4,3,1,100,0,0",
]
How can I sort the list based on the first number in each line with python?
And then, once sorted, remove all duplicates, if any are there?
The sorting criteria for the list is the number before the first comma in each line, which is always an integer.
I tried using list.sort() , however, this sorts the items in lexical order, not numerically.

You could use a dictionary for this. The key will be number before the first comma and the value the entire string. Duplicates will be eliminated, but only the last occurrence of a particular number's string is stored.
l = ['464782,-100,4,3,1,100,0,0',
'465042,-166.666666666667,4,3,1,100,0,0',
'465825,-250.000000000001,4,3,1,100,0,0',
'466868,-166.666666666667,4,3,1,100,0,0',
'467390,-200.000000000001,4,3,1,100,0,0',
...]
d = {int(s.split(',')[0]) : s for s in l}
result = [d[key] for key in sorted(d.keys())]

I would try one of these two methods:
def sort_list(lis):
nums = [int(num) if isdigit(num) else float(num) for num in lis]
nums = list(set(nums))
nums.sort()
return [str(i) for i in nums] # I assumed you wanted them to be strings.
The first will raise a TypeError if all items in lis are not ints, floats, or string representations of a number. The second method doesn't have that problem, but it's a bit wonkier.
def sort_list(lis):
ints = [int(num) for num in lis if num.isdigit()]
floats = [float(num) for num in lis if not num.isdigit()]
nums = ints.copy()
nums.extend(floats)
nums = list(set(nums))
nums.sort()
return [str(i) for i in nums] # I assumed you wanted them to be strings.
Hope this helps.

You can try this.
First we need to remove the duplicates inside the list using set()
removed_duplicates_list = list(set(listr))
Then we convert the list of strings in to a list of tuples
list_of_tuples = [tuple(i.split(",")) for i in removed_duplicates_list]
Then we sort it using the sort()
list_of_tuples.sort()
The complete code sample below:
listr = [
"464782,-100,4,3,1,100,0,0"
"465042,-166.666666666667,4,3,1,100,0,0",
"465825,-250.000000000001,4,3,1,100,0,0",
"466868,-166.666666666667,4,3,1,100,0,0",
"467390,-200.000000000001,4,3,1,100,0,0",
"469999,-100,4,3,1,100,0,0",
"470260,-166.666666666667,4,3,1,100,0,0",
"474173,-100,4,3,1,100,0,0",
"474434,-166.666666666667,4,3,1,100,0,0",
"481477,-100,4,3,1,100,0,1",
"531564,259.011439671919,4,3,1,60,1,0",
"24369,-333.333333333335,4,3,1,100,0,0",
"21082,410.958904109589,4,3,1,60,1,0",
"21082,-250,4,3,1,100,0,0",
"22725,-142.857142857143,4,3,1,100,0,0",
"23547,-166.666666666667,4,3,1,100,0,0",
"24369,-333.333333333335,4,3,1,100,0,0",
"27657,-200.000000000001,4,3,1,100,0,0",
"29301,-142.857142857143,4,3,1,100,0,0",
"30123,-166.666666666667,4,3,1,100,0,0",
"30945,-250,4,3,1,100,0,0",
"32588,-166.666666666667,4,3,1,100,0,0",
"34232,-250,4,3,1,100,0,0",
"35876,-142.857142857143,4,3,1,100,0,0",
"36698,-166.666666666667,4,3,1,100,0,0",
"37520,-250,4,3,1,100,0,0",
"42451,-142.857142857143,4,3,1,100,0,0",
"43273,-166.666666666667,4,3,1,100,0,0",
]
removed_duplicates_list = list(set(listr))
list_of_tuples = [tuple(i.split(",")) for i in removed_duplicates_list]
list_of_tuples.sort()
print(list_of_tuples) # the output is a list of tuples
OUTPUT:
[('21082', '-250', '4', '3', '1', '100', '0', '0'),
('21082', '410.958904109589', '4', '3', '1', '60', '1', '0'),
('22725', '-142.857142857143', '4', '3', '1', '100', '0', '0'),
('23547', '-166.666666666667', '4', '3', '1', '100', '0', '0'),
('24369', '-333.333333333335', '4', '3', '1', '100', '0', '0'),
('27657', '-200.000000000001', '4', '3', '1', '100', '0', '0'),
('29301', '-142.857142857143', '4', '3', '1', '100', '0', '0'),
('30123', '-166.666666666667', '4', '3', '1', '100', '0', '0'),
('30945', '-250', '4', '3', '1', '100', '0', '0'),
('32588', '-166.666666666667', '4', '3', '1', '100', '0', '0'),
('34232', '-250', '4', '3', '1', '100', '0', '0'),
('35876', '-142.857142857143', '4', '3', '1', '100', '0', '0'),
('36698', '-166.666666666667', '4', '3', '1', '100', '0', '0'),
('37520', '-250', '4', '3', '1', '100', '0', '0'),
('42451', '-142.857142857143', '4', '3', '1', '100', '0', '0'),
('43273', '-166.666666666667', '4', '3', '1', '100', '0', '0'),
('464782','-100','4','3','1','100','0'),
('465042','-166.666666666667','4','3','1','100','0','0'),
('465825', '-250.000000000001', '4', '3', '1', '100', '0', '0'),
('466868', '-166.666666666667', '4', '3', '1', '100', '0', '0'),
('467390', '-200.000000000001', '4', '3', '1', '100', '0', '0'),
('469999', '-100', '4', '3', '1', '100', '0', '0'),
('470260', '-166.666666666667', '4', '3', '1', '100', '0', '0'),
('474173', '-100', '4', '3', '1', '100', '0', '0'),
('474434', '-166.666666666667', '4', '3', '1', '100', '0', '0'),
('481477', '-100', '4', '3', '1', '100', '0', '1'),
('531564', '259.011439671919', '4', '3', '1', '60', '1', '0')]

I hope this will help to.
I place all your list elements in a separate file named lista.txt
In this example I will get your list from file... I like to be more organizated and to have separate files you can do in on python as well, but the idea is you need to get all elements from list one by one (while function or for function) and to add them to a temporary list by checking if the new items already exist, if is exist pass and then you can sample use .sort() because will do the trick and with numbers.
# Global variables
file = "lista.txt"
tempList = []
# Logic get items from file
def GetListFromFile(fileName):
# Local variables
showDoneMsg = True
# Try to run this code
try:
# Open file and try to read it
with open(fileName, mode="r") as f:
# Define line
line = f.readline()
# For every line in file
while line:
# Get out all end white space (\n, \r)
item = line.rstrip()
# Check if this item is not allready in the list
if item not in tempList:
# Append item to a temporar list
tempList.append(item)
# Show me if a itmes allready exist
else:
print("Dublicate >>", item)
# Go to new line
line = f.readline()
# This is optional because is callet automatical
# but I like to be shore
f.close()
# Execptions
except FileNotFoundError:
print("ERROR >> File do not exist!")
showDoneMsg = False
# Sort the list
tempList.sort()
# Show me when is done if file exist
if showDoneMsg == True:
print("\n>>> DONE <<<\n")
# Logic show list items
def ShowListItems(thisList):
if len(thisList) == 0:
print("Temporary list is empty...")
else:
print("This is new items list:")
for i in thisList:
print(i)
# Execute function
GetListFromFile(file)
# Testing if items was sorted
ShowListItems(tempList)
Out put:
========================= RESTART: D:\Python\StackOverflow\help.py =========================
Dublicate >> 43273,-166.666666666667,4,3,1,100,0,0
>>> DONE <<<
21082,-250,4,3,1,100,0,0
21082,410.958904109589,4,3,1,60,1,0
22725,-142.857142857143,4,3,1,100,0,0
...
474434,-166.666666666667,4,3,1,100,0,0
481477,-100,4,3,1,100,0,1
531564,259.011439671919,4,3,1,60,1,0
>>>

how to split a list every nth item

I am trying to split a list every 5th item, then delete the next two items ('nan'). I have attempted to use List[:5], but that does not seem to work in a loop. The desired output is: [['1','2','3','4','5'],['1','2','3','4','5'],['1','2','3','4','5'],['1','2','3','4','5']]
List = ['1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan']
for i in List:
# split first 5 items
# delete next two items
# Desired output:
# [['1','2','3','4','5'],['1','2','3','4','5'],['1','2','3','4','5'],['1','2','3','4','5']]

There are lots of ways to do this. I recommend stepping by 7 then splicing by 5.
data = ['1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan']
# Step by 7 and keep the first 5
chunks = [data[i:i+5] for i in range(0, len(data), 7)]
print(*chunks, sep='\n')
Output:
['1', '2', '3', '4', '5']
['1', '2', '3', '4', '5']
['1', '2', '3', '4', '5']
['1', '2', '3', '4', '5']
Reference: Split a python list into other “sublists”...

WARNING: make sure the list follows the rules as you said, after every 5 items 2 nan.
This loop will add the first 5 items as a list, and delete the first 7 items.
lst = ['1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan']
output = []
while True:
if len(lst) <= 0:
break
output.append(lst[:5])
del lst[:7]
print(output) # [['1', '2', '3', '4', '5'], ['1', '2', '3', '4', '5'], ['1', '2', '3', '4', '5'], ['1', '2', '3', '4', '5']]

List=['1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan']
new_list = list()
for k in range(len(List)//7):
new_list.append(List[k*7:k*7+5])
new_list.append(List[-len(List)%7])

Straightforward solution in case if the list doesn’t follow the rules you mentioned but you want to split sequence always between NAN's:
result, temp = [], []
for item in lst:
if item != 'nan':
temp.append(item)
elif temp:
result.append(list(temp))
temp = []

Using itertools.groupby would also support chunks of different lengths:
[list(v) for k, v in groupby(List, key='nan'.__ne__) if k]

I guess there is more pythonic way to do the same but:
result = []
while (len(List) > 5):
result.append(List[0:0+5])
del List[0:0+5]
del List[0:2]
This results: [['1', '2', '3', '4', '5'], ['1', '2', '3', '4', '5'], ['1', '2', '3', '4', '5'], ['1', '2', '3', '4', '5']]

mainlist=[]
sublist=[]
count=0
for i in List:
if i!="nan" :
if count==4:
# delete next two items
mainlist.append(sublist)
count=0
sublist=[]
else:
# split first 5 items
sublist.append(i)
count+=1

Generally numpy.split(...) will do any kind of custom splitting for you. Some reference:
https://docs.scipy.org/doc/numpy/reference/generated/numpy.split.html
And the code:
import numpy as np
lst = ['1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan','1','2','3','4','5','nan','nan']
ind=np.ravel([[i*7+5, (i+1)*7] for i in range(len(lst)//7)])
lst2=np.split(lst, ind)[:-1:2]
print(lst2)
Outputs:
[array(['1', '2', '3', '4', '5'], dtype='<U3'), array(['1', '2', '3', '4', '5'], dtype='<U3'), array(['1', '2', '3', '4', '5'], dtype='<U3'), array(['1', '2', '3', '4', '5'], dtype='<U3')]

I like the splice answers.
Here is my 2 cents.
# changed var name away from var type
myList = ['1','2','3','4','5','nan','nan','1','2','3','4','10','nan','nan','1','2','3','4','15','nan','nan','1','2','3','4','20','nan','nan']
newList = [] # declare new list of lists to create
addItem = [] # declare temp list
myIndex = 0 # declare temp counting variable
for i in myList:
myIndex +=1
if myIndex==6:
nothing = 0 #do nothing
elif myIndex==7: #add sub list to new list and reset variables
if len(addItem)>0:
newList.append(list(addItem))
addItem=[]
myIndex = 0
else:
addItem.append(i)
#output
print(newList)

Is there a way to generate a list string within Python, without any other 3rd party packages?

this code generates a list of integers
dir_list = list(range(11))
dir_list
numpy could transfer each element to string type
import numpy as np
dir_list = np.array(dir_list, dtype=np.str)
dir_list
array(['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '10'],
dtype='<U2')
is there a way to finish the job within Python, without any other 3rd party packages?

You can simply map each integer to string using inbuilt map function and map returns iterator so you can convert it into list.
list(map(str, range(11))) should do.
output:
['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '10']

Of course, this way you can iterate over each element of range object and convert to str and store as list:
dir_list = [str(i) for i in range(11)]
>>> dir_list
['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '10']

Python few elements of the list were skipped while removing them in for loop

I am wondering what is the reason why some elements weren't removed in this program. Could someone provide pointers?
Program:
t = ['1', '2', '2', '2', '2', '2', '2', '2', '2', '2', '7', '8', '9', '10']
print len(t)
for x in t:
if x == '2':
print x
t.remove(x)
else:
print 'hello: '+str(x)
print t
Output on my system:
14
hello: 1
2
2
2
2
2
hello: 8
hello: 9
hello: 10
['1', '2', '2', '2', '2', '7', '8', '9', '10']
I am using Python 2.6.2.

Never alter the sequence on which you're iterating.
#cjonhson318's list-comprehension will work fine, or, less efficiently but more closely akin to your code, just loop on a copy of the list while you're altering the list itself:
for x in list(t):
if x == '2':
print x
t.remove(x)
else:
print 'hello: '+str(x)
As you see the only change from your code is looping on list(t) (a copy of t's initial value) rather than on t itself -- this modest change lets you alter t itself within the loop to your heart's contents.

Say something like:
t = [ i for i in t if i != '2' ]
for item in t:
print "Hello "+item

An alternative would be to get functional
from operator import ne
from functools import partial
t = ['1', '2', '2', '2', '2', '2', '2', '2', '2', '2', '7', '8', '9', '10']
for n in filter(partial(ne, '2'), t):
print('hello {}'.format(n))
Use the filter function to create a new list minus the 2 values.
If the use of partial and operator.ne was not to your liking, you could use a lambda
for n in filter(lambda x: x != '2', t):
print('hello {}'.format(n))

How could i refresh a list once an item has been removed from a list within a list in python

This is quite complicated but i would like to be able to refresh a larger list once at item has been taken out of a mini list within the bigger list.
listA = ['1','2','3','4','5','6','6','8','9','5','3','7']
i used the code below to split it into lists of threes
split = [listA[i:(i+3)] for i in range(0, len(listA) - 1, 3)]
print(split)
# [['1','2','3'],['4','5','6'],['6','8','9'],['5','3','7']]
split = [['1','2','3'],['4','5','6'],['6','8','9'],['5','3','7']]
if i deleted #3 from the first list, split will now be
del split[0][-1]
split = [['1','2'],['4','5','6'],['6','8','9'],['5','3','7']]
after #3 has been deleted, i would like to be able to refresh the list so that it looks like;
split = [['1','2','4'],['5','6','6'],['8','9','5'],['3','7']]
thanks in advance

Not sure how big this list is getting, but you would need to flatten it and recalculate it:
>>> listA = ['1','2','3','4','5','6','6','8','9','5','3','7']
>>> split = [listA[i:(i+3)] for i in range(0, len(listA) - 1, 3)]
>>> split
[['1', '2', '3'], ['4', '5', '6'], ['6', '8', '9'], ['5', '3', '7']]
>>> del split[0][-1]
>>> split
[['1', '2'], ['4', '5', '6'], ['6', '8', '9'], ['5', '3', '7']]
>>> listA = sum(split, []) # <- flatten split list back to 1 level
>>> listA
['1', '2', '4', '5', '6', '6', '8', '9', '5', '3', '7']
>>> split = [listA[i:(i+3)] for i in range(0, len(listA) - 1, 3)]
>>> split
[['1', '2', '4'], ['5', '6', '6'], ['8', '9', '5'], ['3', '7']]

Just recreate the single list from your nested lists, then re-split.
You can join the lists, assuming they are only one level deep, with something like:
rejoined = [element for sublist in split for element in sublist]
There are no doubt fancier ways, or single-liners that use itertools or some other library, but don't overthink it. If you're only talking about a few hundred or even a few thousand items this solution is quite good enough.

I need this for turning of cards in the deck in a solitaire game.
You can deal your cards using itertools.groupby() with a good key function:
def group_key(x, n=3, flag=[0], counter=itertools.count(0)):
if next(counter) % n == 0:
flag[0] = flag[0] ^ 1
return flag[0]
^ is a bitwise operator, basically it change the value of the flag from 0 to 1 and viceversa. The flag value is an element of a list because we're doing some kind of memoization.
Example:
>>> deck = ['1', '2', '3', '4', '5', '6', '6', '8', '9', '5', '3', '7']
>>> for k,g in itertools.groupby(deck, key=group_key):
... print(list(g))
['1', '2', '3']
['4', '5', '6']
['6', '8', '9']
['5', '3', '7']
Now let's say you've used card '9' and '8', so your new deck looks like:
>>> deck = ['1', '2', '3', '4', '5', '6', '6', '5', '3', '7']
>>> for k,g in itertools.groupby(deck, key=group_key):
... print(list(g))
['1', '2', '3']
['4', '5', '6']
['6', '5', '3']
['7']

Build an object that contains a list and tracks when the list is altered (probably by controlling write to it), then have the object do it's own split every time the data is altered and save the split list to a member of the object.