How to re-map keys on Ubuntu?

https://github.com/sezanzeb/input-remapper

 

How to sort a 2 dimensional list by 2 or more keys in different orders in Python?

https://wiki.python.org/moin/HowTo/Sorting/#Key_Functions

If with Pandas, it is easy - 

dist_list = [            

    [Ada Taylor, 4.00],

    [Iris White,26.02],

    [Octavia Smith, 7.29],

    [Tracy Jones, 4.00],

]

# Convert the list into a Python dataframe.

dist_df = pd.DataFrame(dist_list, columns=['Name', 'Distance'])

# Sort it by Distance in descending order. If some people 

# run the same distance, then sort those people's distances 

# by Name in ascending order.

dist_df.sort_values(by=['Distance', 'Name'], ascending=(False, True), inplace=True)

print(dist_df)

            Name  Distance

0     Iris White     26.02

1  Octavia Smith      7.29

2     Ada Taylor      4.00

3    Tracy Jones      4.00

But if without Pandas, we can manage to do that by sorting it twice. Firstly sort it by the secondary key (Name) in one order (ascending), then sort it by the main key (Distance) in another order (descending).

# Convert the list into a dictionary, while grouping

# and aggregating the distances by person.

dist_dict = {}

for person, distance in dist_list:

    if person not in dist_dict:

        dist_dict[person] = distance

    else:

        dist_dict[person] += distance

# Convert the dictionary back into a list, in order to sort it.

dist_list = [[person, distance] for person, distance in dist_dict.items()]

# Firstly, sort it by secondary key - person, in ascending order.

dist_list = sorted(dist_list, key=lambda x: x[0], reverse=False)

# Then, sort it by primary key - distance, in descending order.

dist_list = sorted(dist_list, key=lambda x: x[1], reverse=True)

print(dist_list)

[['Iris White', 26.02], ['Octavia Smith', 7.29], ['Ada Taylor', 4], ['Tracy Jones', 4]]

We can also manage to do that using the 'itemgetter()' function from the 'operator' Python standard module.

from operator import itemgetter

dist_list = sorted(dist_list, itemgetter(0), reverse=False)

dist_list = sorted(dist_list, itemgetter(1), reverse=True)

print(dist_list)

[['Iris White', 26.02], ['Octavia Smith', 7.29], ['Ada Taylor', 4], ['Tracy Jones', 4]]

Please look at 

https://wiki.python.org/moin/HowTo/Sorting/#Key_Functions

I copied the section here as follows.

Operator Module Functions

The key-function patterns shown above are very common, so Python provides convenience functions to make accessor functions easier and faster. The operator module has itemgetter, attrgetter, and starting in Python 2.6 a methodcaller function.

Using those functions, the above examples become simpler and faster.

>>> from operator import itemgetter, attrgetter, methodcaller

>>> sorted(student_tuples, key=itemgetter(2))
[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

>>> sorted(student_objects, key=attrgetter('age'))
[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

The operator module functions allow multiple levels of sorting. For example, to sort by grade then by age:

>>> sorted(student_tuples, key=itemgetter(1,2))
[('john', 'A', 15), ('dave', 'B', 10), ('jane', 'B', 12)]

>>> sorted(student_objects, key=attrgetter('grade', 'age'))
[('john', 'A', 15), ('dave', 'B', 10), ('jane', 'B', 12)]

The third function from the operator module, methodcaller is used in the following example in which the weighted grade of each student is shown before sorting on it:

>>> [(student.name, student.weighted_grade()) for student in student_objects]
[('john', 0.13333333333333333), ('jane', 0.08333333333333333), ('dave', 0.1)]
>>> sorted(student_objects, key=methodcaller('weighted_grade'))
[('jane', 'B', 12), ('dave', 'B', 10), ('john', 'A', 15)]

Ascending and Descending

Both list.sort() and sorted() accept a reverse parameter with a boolean value. This is using to flag descending sorts. For example, to get the student data in reverse age order:

>>> sorted(student_tuples, key=itemgetter(2), reverse=True)
[('john', 'A', 15), ('jane', 'B', 12), ('dave', 'B', 10)]

>>> sorted(student_objects, key=attrgetter('age'), reverse=True)
[('john', 'A', 15), ('jane', 'B', 12), ('dave', 'B', 10)]

Sort Stability and Complex Sorts

Starting with Python 2.2, sorts are guaranteed to be stable. That means that when multiple records have the same key, their original order is preserved.

>>> data = [('red', 1), ('blue', 1), ('red', 2), ('blue', 2)]
>>> sorted(data, key=itemgetter(0))
[('blue', 1), ('blue', 2), ('red', 1), ('red', 2)]

Notice how the two records for 'blue' retain their original order so that ('blue', 1) is guaranteed to precede ('blue', 2).

This wonderful property lets you build complex sorts in a series of sorting steps. For example, to sort the student data by descending grade and then ascending age, do the age sort first and then sort again using grade:

>>> s = sorted(student_objects, key=attrgetter('age'))     # sort on secondary key
>>> sorted(s, key=attrgetter('grade'), reverse=True)       # now sort on primary key, descending
[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

The Timsort algorithm used in Python does multiple sorts efficiently because it can take advantage of any ordering already present in a dataset.

Using Public Keys for SSH Authentication

Using PuTTYgen

Set up SSH public key authentication

Generate Key Pair

If you do not have a key pair yet, start with generating new key pair.

Configure Server to Accept Public Key

Connect to your SSH server using WinSCP with the SSH protocol, using other means of authentication than public key, e.g. typically using password authentication.
Once logged in, configure your server to accept your public key. That varies with SSH server software being used. The most common SSH server is OpenSSH.

OpenSSH

• Navigate into a .ssh subdirectory of your account home directory. You may need to enable showing hidden files to see the directory. If the directory does not exists, you need to create it first.
• Once there, open a file authorized_keys for editing. Again you may have to create this file, if this is your first key.
• Switch to the PuTTYgen window, select all of the text in the Public key for pasting into authorized_keys file box, and copy it to the clipboard (Ctrl+C). Then, switch back to the editor and insert the data into the open file, making sure it ends up all on one line. Save the file.
• Ensure that your account home directory, your .ssh directory and file authorized_keys are not group-writable or world-writable. Recommended permissions for .ssh directory are 700. Recommended permissions for authorized_keys files are 600. Read more about changing permissions.

ssh.com

• Save a public key file from PuTTYgen, and copy that into the .ssh2 subdirectory of your account home directory.
• In the same subdirectory, edit (or create) a file called authorization. In this file you should put a line like Key mykey.pub, with mykey.pub replaced by the name of your key file.

Other SSH Servers

For other SSH server software, you should refer to the manual for that server.

Configure WinSCP Session

When configuring session, specify path to your private key on SSH > Authentication page of Advanced Site Settings dialog.
Alternatively, load the private key into Pageant.