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Python: Fill data in a list in a tuple

I need to create a function that reads the data given and creates a list that contains tuples each of which has as its first element the name of the airport and as its second and third its geographical coordinates as float numbers.
airport_data = """
Alexandroupoli 40.855869°N 25.956264°E
Athens 37.936389°N 23.947222°E
Chania 35.531667°N 24.149722°E
Chios 38.343056°N 26.140556°E
Corfu 39.601944°N 19.911667°E
Heraklion 35.339722°N 25.180278°E"""
airports = []
import re
airport_data1 = re.sub("[°N#°E]","",airport_data)
def process_airports(string):
airports_temp = list(string.split())
airports = [tuple(airports_temp[x:x+3]) for x in range(0, len(airports_temp), 3)]
return airports
print(process_airports(airport_data1))
This is my code so far but I'm new to Python, so I'm struggling to debug my code.

If you want the second and third element of the tuple to be a float, you have to convert them using the float() function.
One way to do this is creating a tuple with round brackets in your list comprehension and convert the values there:
def process_airports(string):
airports_temp = string.split()
airports = [(airports_temp[x], float(airports_temp[x+1]), float(airports_temp[x+2])) for x in range(0, len(airports_temp), 3)]
return airports
This yields a pretty unwieldy expression, so maybe this problem could be solved more readable with a classical for loop.
Also note that slpit() already returns a list.
Further remark: If you just cut off the letters from coordinates this might come back to bite you when your airports are in different quadrants.

You need to take in account N/S, W/E for longitude and latitude.
May be
def process_airports(string):
airports = []
for line in string.split('\n'):
if not line: continue
name, lon, lat = line.split()
airports.append((name,
float(lon[:-2]) * (1 if lon[-1] == "N" else -1),
float(lat[:-2]) * (-1 if lat[-1] == "E" else 1)
))
return airports
>>> process_airports(airport_data1)
[('Alexandroupoli', 40.855869, -25.956264), ('Athens', 37.936389, -23.947222), ('Chania', 35.531667, -24.149722), ('Chios', 38.343056, -26.140556), ('Corfu', 39.601944, -19.911667), ('Heraklion', 35.339722, -25.180278)]
I prefered the double split to put in evidence the differences lines/tuple elements

How to sort a list of strings delimited by '.' with also numbers in the middle?

I have a list of strings that contain commands separated by a dot . like this:
DeviceA.CommandA.1.Hello,
DeviceA.CommandA.2.Hello,
DeviceA.CommandA.11.Hello,
DeviceA.CommandA.3.Hello,
DeviceA.CommandB.1.Hello,
DeviceA.CommandB.1.Bye,
DeviceB.CommandB.What,
DeviceA.SubdeviceA.CommandB.1.Hello,
DeviceA.SubdeviceA.CommandB.2.Hello,
DeviceA.SubdeviceB.CommandA.1.What
And I would want to order them in natural order:
The order must prioritize by field index (e.g The commands that start with DeviceA will always go before DeviceB etc)
Order alphabetically the strings
When it finds a number sort numerically in ascending order
Therefore, the sorted output should be:
DeviceA.CommandA.1.Hello,
DeviceA.CommandA.2.Hello,
DeviceA.CommandA.3.Hello,
DeviceA.CommandA.11.Hello,
DeviceA.CommandB.1.Bye,
DeviceA.CommandB.1.Hello,
DeviceA.SubdeviceA.CommandB.1.Hello,
DeviceA.SubdeviceA.CommandB.2.Hello,
DeviceA.SubdeviceB.CommandA.What,
DeviceB.CommandB.What
Also note that the length of the command fields is dynamic, the number of fields separated by dot can be any size.
So far I tried this without luck (the numbers are order alphabetically, for example 11 goes before 5):
list = [
"DeviceA.CommandA.1.Hello",
"DeviceA.CommandA.2.Hello",
"DeviceA.CommandA.11.Hello",
"DeviceA.CommandA.3.Hello",
"DeviceA.CommandB.1.Hello",
"DeviceA.CommandB.1.Bye",
"DeviceB.CommandB.What",
"DeviceA.SubdeviceA.CommandB.1.Hello",
"DeviceA.SubdeviceA.CommandB.2.Hello",
"DeviceA.SubdeviceB.CommandA.1.What"
]
sorted_list = sorted(list, key=lambda x: x.split('.'))
EDIT: Corrected typo error.

Something like this should get you going.
from pprint import pprint
data_list = [
"DeviceA.CommandA.1.Hello",
"DeviceA.CommandA.2.Hello",
"DeviceA.CommandA.3.Hello",
"DeviceA.CommandB.1.Hello",
"DeviceA.CommandB.1.Bye",
"DeviceB.CommandB.What",
"DeviceA.SubdeviceA.CommandB.1.Hello",
"DeviceA.SubdeviceA.CommandB.15.Hello", # added test case to ensure numbers are sorted numerically
"DeviceA.SubdeviceA.CommandB.2.Hello",
"DeviceA.SubdeviceB.CommandA.1.What",
]
def get_sort_key(s):
# Turning the pieces to integers would fail some comparisons (1 vs "What")
# so instead pad them on the left to a suitably long string
return [
bit.rjust(30, "0") if bit.isdigit() else bit
for bit in s.split(".")
]
# Note the key function must be passed as a kwarg.
sorted_list = sorted(data_list, key=get_sort_key)
pprint(sorted_list)
The output is
['DeviceA.CommandA.1.Hello',
'DeviceA.CommandA.2.Hello',
'DeviceA.CommandA.3.Hello',
'DeviceA.CommandB.1.Bye',
'DeviceA.CommandB.1.Hello',
'DeviceA.SubdeviceA.CommandB.1.Hello',
'DeviceA.SubdeviceA.CommandB.2.Hello',
'DeviceA.SubdeviceA.CommandB.15.Hello',
'DeviceA.SubdeviceB.CommandA.1.What',
'DeviceB.CommandB.What']

Specifying a key in sorted seems to achieve what you want:
import re
def my_key(s):
n = re.search("\d+",s)
return (s[:n.span()[0]], int(n[0])) if n else (s,)
print(sorted(l, key = my_key))
Output:
['DeviceA.CommandA.1.Hello', 'DeviceA.CommandA.2.Hello', 'DeviceA.CommandA.3.Hello', 'DeviceA.CommandA.11.Hello', 'DeviceA.CommandB.1.Hello', 'DeviceA.CommandB.1.Bye', 'DeviceA.SubdeviceA.CommandB.1.Hello', 'DeviceA.SubdeviceA.CommandB.2.Hello', 'DeviceA.SubdeviceB.CommandA.1.What', 'DeviceB.CommandB.What']

There are many ways to achieve this. Here's one that doesn't rely on importation of any additional modules:
LOS = ['DeviceA.CommandA.1.Hello',
'DeviceA.CommandA.2.Hello',
'DeviceA.CommandA.11.Hello',
'DeviceA.CommandA.3.Hello',
'DeviceA.CommandB.1.Hello',
'DeviceA.CommandB.1.Bye',
'DeviceB.CommandB.What',
'DeviceA.SubdeviceA.CommandB.1.Hello',
'DeviceA.SubdeviceA.CommandB.2.Hello',
'DeviceA.SubdeviceB.CommandA.1.What']
def func(s):
tokens = s.split('.')
for i, token in enumerate(tokens):
try:
v = int(token)
return ('.'.join(tokens[0:i]), v)
except ValueError:
pass
return (s, 0)
print(sorted(LOS, key=func))

selecting a value using a conditional statement based on a list of tuples

I have a list of tuples converted from a dictionary. I am looking to compare a conditional value against the list of tuples(values) whether it is higher or lower starting from the beginning on the list. When this conditional value is lower than a tuple's(value) I want to use that specific tuple for further coding.
Please can somebody give me an insight into how this is achieved?
I am relatively new to coding, self-learning and I am not 100% sure the example would run but for the sake of demonstrating I have tried my best.
`tuple_list = [(12:00:00, £55.50), (13:00:00, £65.50), (14:00:00, £75.50), (15:00:00, £45.50), (16:00:00, £55.50)]
conditional_value = £50
if conditional_value != for x in tuple_list.values()
y = 0
if conditional_value < tuple_list(y)
y++1
else
///"return the relevant value from the tuple_list to use for further coding. I would be
looking to work with £45.50"///`
Thank you.

Just form a new list with a condition:
tuple_list = [("12:00:00", 55.50), ("13:00:00", 65.50), ("14:00:00", 75.50), ("15:00:00", 45.50), ("16:00:00", 55.50)]
threshold = 50
below = [tpl for tpl in tuple_list if tpl[1] < threshold]
print(below)
Which yields
[('15:00:00', 45.5)]
Note that I added quotation marks and removed the currency sign to be able to compare the values. If you happen to have the £ in your actual values, you'll have to preprocess (stripping) them before.

If I'm understanding your question correctly, this should be what you're looking for:
for key, value in tuple_list:
if conditional_value < value:
continue # Skips to next in the list.
else:
# Do further coding.

You can use
tuple_list = [("12:00:00", 55.50), ("13:00:00", 65.50), ("14:00:00", 75.50), ("15:00:00", 45.50), ("16:00:00", 55.50)]
conditional_value = 50
new_tuple_list = list(filter(lambda x: x[1] > conditional_value, tuple_list))
This code will return a new_tuple_list with all items that there value us greater then the conditional_value.

Outputting Bubble sorting

I have this list called countries.txt that list all the countries by their name, area(in km2), population (eg. ["Afghanistan", 647500.0, 25500100]).
def readCountries(filename):
result=[]
lines=open(filename)
for line in lines:
result.append(line.strip('\n').split(',\t'))
for sublist in result:
sublist[1]=float(sublist[1])
sublist[2]=int(sublist[2])
I am trying to sort through the list using a bubble sort according to the are of each country:
>> c = countryByArea(7)
>>> c
>>["India",3287590.0,1239240000]
When typing in the parameter is should return the nth largest area.
I have this but I'm not sure how to output the information
def countryByArea(area):
myList=readCountries('countries.txt')
for i in range(0,len(list)):
for j in range(0,len(list)-1):
if list[j]>list[j+1]:
temp=list[j]
list[j]=list[j+1]
list[j+1]=temp

first of all, implement a generic bubble sort method. this is a correct bubble sort algorithm implementation... Im sure you can find other implementations on http://rosettacode.org
def bubble_sort(a_list,a_key):
changed=True
while changed:
changed = False
for i in range(len(a_list)-1):
if a_key(a_list[i]) > a_key(a_list[i+1]):
a_list[i],a_list[i+1] = a_list[i+1],a_list[i]
changed = True
then simply pass a key function that represents the data you want to sort by (in this case the middle value or index one of each row
import csv
def sort_by_area(fname):
with open(fname) as f:
a = list(csv.reader(f))
bubble_sort(a,lambda row:int(row[1]))
return a
a = sort_by_area("a_file.txt")
print a[-7] #the 7th largest by area
you can take this info and combine it to complete your assignment ... but really this is a question you should have asked a classmate or your teacher for help with ...

Sorting with two digits in string - Python

I am new to Python and I have a hard time solving this.
I am trying to sort a list to be able to human sort it 1) by the first number and 2) the second number. I would like to have something like this:
'1-1bird'
'1-1mouse'
'1-1nmouses'
'1-2mouse'
'1-2nmouses'
'1-3bird'
'10-1birds'
(...)
Those numbers can be from 1 to 99 ex: 99-99bird is possible.
This is the code I have after a couple of headaches. Being able to then sort by the following first letter would be a bonus.
Here is what I've tried:
#!/usr/bin/python
myList = list()
myList = ['1-10bird', '1-10mouse', '1-10nmouses', '1-10person', '1-10cat', '1-11bird', '1-11mouse', '1-11nmouses', '1-11person', '1-11cat', '1-12bird', '1-12mouse', '1-12nmouses', '1-12person', '1-13mouse', '1-13nmouses', '1-13person', '1-14bird', '1-14mouse', '1-14nmouses', '1-14person', '1-14cat', '1-15cat', '1-1bird', '1-1mouse', '1-1nmouses', '1-1person', '1-1cat', '1-2bird', '1-2mouse', '1-2nmouses', '1-2person', '1-2cat', '1-3bird', '1-3mouse', '1-3nmouses', '1-3person', '1-3cat', '2-14cat', '2-15cat', '2-16cat', '2-1bird', '2-1mouse', '2-1nmouses', '2-1person', '2-1cat', '2-2bird', '2-2mouse', '2-2nmouses', '2-2person']
def mysort(x,y):
x1=""
y1=""
for myletter in x :
if myletter.isdigit() or "-" in myletter:
x1=x1+myletter
x1 = x1.split("-")
for myletter in y :
if myletter.isdigit() or "-" in myletter:
y1=y1+myletter
y1 = y1.split("-")
if x1[0]>y1[0]:
return 1
elif x1[0]==y1[0]:
if x1[1]>y1[1]:
return 1
elif x1==y1:
return 0
else :
return -1
else :
return -1
myList.sort(mysort)
print myList
Thanks !
Martin

You have some good ideas with splitting on '-' and using isalpha() and isdigit(), but then we'll use those to create a function that takes in an item and returns a "clean" version of the item, which can be easily sorted. It will create a three-digit, zero-padded representation of the first number, then a similar thing with the second number, then the "word" portion (instead of just the first character). The result looks something like "001001bird" (that won't display - it'll just be used internally). The built-in function sorted() will use this callback function as a key, taking each element, passing it to the callback, and basing the sort order on the returned value. In the test, I use the * operator and the sep argument to print it without needing to construct a loop, but looping is perfectly fine as well.
def callback(item):
phrase = item.split('-')
first = phrase[0].rjust(3, '0')
second = ''.join(filter(str.isdigit, phrase[1])).rjust(3, '0')
word = ''.join(filter(str.isalpha, phrase[1]))
return first + second + word
Test:
>>> myList = ['1-10bird', '1-10mouse', '1-10nmouses', '1-10person', '1-10cat', '1-11bird', '1-11mouse', '1-11nmouses', '1-11person', '1-11cat', '1-12bird', '1-12mouse', '1-12nmouses', '1-12person', '1-13mouse', '1-13nmouses', '1-13person', '1-14bird', '1-14mouse', '1-14nmouses', '1-14person', '1-14cat', '1-15cat', '1-1bird', '1-1mouse', '1-1nmouses', '1-1person', '1-1cat', '1-2bird', '1-2mouse', '1-2nmouses', '1-2person', '1-2cat', '1-3bird', '1-3mouse', '1-3nmouses', '1-3person', '1-3cat', '2-14cat', '2-15cat', '2-16cat', '2-1bird', '2-1mouse', '2-1nmouses', '2-1person', '2-1cat', '2-2bird', '2-2mouse', '2-2nmouses', '2-2person']
>>> print(*sorted(myList, key=callback), sep='\n')
1-1bird
1-1cat
1-1mouse
1-1nmouses
1-1person
1-2bird
1-2cat
1-2mouse
1-2nmouses
1-2person
1-3bird
1-3cat
1-3mouse
1-3nmouses
1-3person
1-10bird
1-10cat
1-10mouse
1-10nmouses
1-10person
1-11bird
1-11cat
1-11mouse
1-11nmouses
1-11person
1-12bird
1-12mouse
1-12nmouses
1-12person
1-13mouse
1-13nmouses
1-13person
1-14bird
1-14cat
1-14mouse
1-14nmouses
1-14person
1-15cat
2-1bird
2-1cat
2-1mouse
2-1nmouses
2-1person
2-2bird
2-2mouse
2-2nmouses
2-2person
2-14cat
2-15cat
2-16cat

You need leading zeros. Strings are sorted alphabetically with the order different from the one for digits. It should be
'01-1bird'
'01-1mouse'
'01-1nmouses'
'01-2mouse'
'01-2nmouses'
'01-3bird'
'10-1birds'
As you you see 1 goes after 0.

The other answers here are very respectable, I'm sure, but for full credit you should ensure that your answer fits on a single line and uses as many list comprehensions as possible:
import itertools
[''.join(r) for r in sorted([[''.join(x) for _, x in
itertools.groupby(v, key=str.isdigit)]
for v in myList], key=lambda v: (int(v[0]), int(v[2]), v[3]))]
That should do nicely:
['1-1bird',
'1-1cat',
'1-1mouse',
'1-1nmouses',
'1-1person',
'1-2bird',
'1-2cat',
'1-2mouse',
...
'2-2person',
'2-14cat',
'2-15cat',
'2-16cat']