Please Help me. I&#39;m running a simple python program that will display the data from mySQL database in a tkinter form...

    from Tkinter import *
    import MySQLdb

    def button_click():
        root.destroy()

    root = Tk()
    root.geometry(&quot;600x500+10+10&quot;)
    root.title(&quot;Ariba&quot;)

    myContainer = Frame(root)
    myContainer.pack(side=TOP, expand=YES, fill=BOTH)

    db = MySQLdb.connect (&quot;localhost&quot;,&quot;root&quot;,&quot;&quot;,&quot;chocoholics&quot;)
    s = &quot;Select * from member&quot;
    cursor = db.cursor()
    cursor.execute(s)
    rows = cursor.fetchall()

    x = rows[1][1] + &quot; &quot; + rows[1][2]
    myLabel1 = Label(myContainer, text = x)
    y = rows[2][1] + &quot; &quot; + rows[2][2]
    myLabel2 = Label(myContainer, text = y)
    btn = Button(myContainer, text = &quot;Quit&quot;, command=button_click, height=1, width=6)

    myLabel1.pack(side=TOP, expand=NO, fill=BOTH)
    myLabel2.pack(side=TOP, expand=NO, fill=BOTH)
    btn.pack(side=TOP, expand=YES, fill=NONE)


Thats the whole program....

The error was 

    x = rows[1][1] + &quot; &quot; + rows[1][2]
    IndexError: tuple index out of range
       
    y = rows[2][1] + &quot; &quot; + rows[2][2]
    IndexError: tuple index out of range

Can anyone help me??? im new in python.

Thank you so much....


IndexError: tuple index out of range ----- Python

This message is a a bit long with many examples, but I hope it
will help me and others to better grasp the full story of variables
and attribute lookup in Python 2.7. 

I am using the terms of PEP 227
(http://www.python.org/dev/peps/pep-0227/) for code blocks (such as
modules, class definition, function definitions, etc.) and
variable bindings (such as assignments, argument declarations, class
and function declaration, for loops, etc.)

I am using the terms variables for names that can be called without a
dot, and attributes for names that need to be qualified with an object
name (such as obj.x for the attribute x of object obj).

There are three scopes in Python for all code blocks, but the functions:

 - Local
 - Global
 - Builtin


There are four blocks in Python for the functions only (according to
PEP 227):

 - Local
 - Enclosing functions
 - Global
 - Builtin

The rule for a variable to bind it to and find it in a block is
quite simple:

 - any binding of a variable to an object in a block makes this variable
local to this block, unless the variable is declared global (in that
case the variable belongs to the global scope)
 - a reference to a variable is looked up using the rule LGB (local,
global, builtin) for all blocks, but the functions
 - a reference to a variable is looked up using the rule LEGB (local,
enclosing, global, builtin) for the functions only. 

Let me know take examples validating this rule, and showing many
special cases. For each example, I will give my understanding. Please
correct me if I am wrong. For the last example, I don&#39;t understand the
outcome. 

example 1:

    x = &quot;x in module&quot;
    class A():
        print &quot;A: &quot;  + x                    #x in module
        x = &quot;x in class A&quot;
        print locals()
        class B():
            print &quot;B: &quot; + x                 #x in module
            x = &quot;x in class B&quot;
            print locals()
            def f(self):
                print &quot;f: &quot; + x             #x in module
                self.x = &quot;self.x in f&quot;
                print x, self.x
                print locals()
 
    &gt;&gt;&gt;A.B().f()
    A: x in module
    {&#39;x&#39;: &#39;x in class A&#39;, &#39;__module__&#39;: &#39;__main__&#39;}
    B: x in module
    {&#39;x&#39;: &#39;x in class B&#39;, &#39;__module__&#39;: &#39;__main__&#39;}
    f: x in module
    x in module self.x in f
    {&#39;self&#39;: &lt;__main__.B instance at 0x00000000026FC9C8&gt;}

There is no nested scope for the classes (rule LGB) and a function in
a class cannot access the attributes of the class without using a
qualified name (self.x in this example). This is well described in
PEP227. 

example 2:

    z = &quot;z in module&quot;
    def f():
        z = &quot;z in f()&quot;
        class C():
            z = &quot;z in C&quot;
            def g(self):
                print z
                print C.z
        C().g()
    f()
    &gt;&gt;&gt; 
    z in f()
    z in C

Here variables in functions are looked up using the LEGB rule, but if
a class is in the path, the class arguments are skipped. Here again,
this is what PEP 227 is explaining.

example 3: 

    var = 0
    def func():
        print var
        var = 1
    &gt;&gt;&gt; func()

    Traceback (most recent call last):
      File &quot;&lt;pyshell#102&gt;&quot;, line 1, in &lt;module&gt;
	func()
      File &quot;C:/Users/aa/Desktop/test2.py&quot;, line 25, in func
	print var
    UnboundLocalError: local variable &#39;var&#39; referenced before assignment


We expect with a dynamic language such as python that everything is
resolved dynamically. But this is not the case for functions. Local
variables are determined at compile time. PEP 227  and 
http://docs.python.org/2.7/reference/executionmodel.html describe this
behavior this way

 &quot;If a name binding operation occurs anywhere within a code block, all
uses of the name within the block are treated as references to the
current block.&quot;

example 4: 

    x = &quot;x in module&quot;
    class A():
        print &quot;A: &quot; + x
        x = &quot;x in A&quot;
        print &quot;A: &quot; + x
        print locals()
        del x
        print locals()
        print &quot;A: &quot; + x
    &gt;&gt;&gt; 
    A: x in module
    A: x in A
    {&#39;x&#39;: &#39;x in A&#39;, &#39;__module__&#39;: &#39;__main__&#39;}
    {&#39;__module__&#39;: &#39;__main__&#39;}
    A: x in module

But we see here that this statement in PEP227 &quot;If a name binding
operation occurs anywhere within a code block, all uses of the name
within the block are treated as references to the current block.&quot;  is
wrong when the code block is a class. Moreover, for classes, it seems
that local name binding is not made at compile time, but during
execution using the class namespace. In that respect,
PEP227 and the execution model in the Python doc is misleading and for
some parts wrong. 

example 5:

    x = &#39;x in module&#39;
    def  f2():
        x = &#39;x in f2&#39;
        def myfunc():
            x = &#39;x in myfunc&#39;
            class MyClass(object):
                x = x
                print x
            return MyClass
        myfunc()
    f2()
    &gt;&gt;&gt; 
    x in module

my understanding of this code is the following. The instruction x = x
first look up the object the right hand x of the expression is referring
to. In that case, the object is looked up locally in the class, then
following the rule LGB it is looked up in the global scope, which is
the string &#39;x in module&#39;. Then a local attribute x to MyClass is
created in the class dictionary and pointed to the string object. 

example 6: 

Now here is an example I cannot explain.
It is very close to example 5, I am just changing the local MyClass
attribute from x to y.

    x = &#39;x in module&#39;
    def  f2():
        x = &#39;x in f2&#39;
        def myfunc():
            x = &#39;x in myfunc&#39;
            class MyClass(object):
                y = x
                print y
            return MyClass
        myfunc()
    f2()
    &gt;&gt;&gt;
    x in myfunc

Why in that case the x reference in MyClass is looked up in the
innermost function? 



How references to variables are resolved in Python

I am using the following `sed` command to replace some parameters in a config file:

    sed -i &#39;s/^option.*/option=value/g&#39; /etc/fdm_monitor.conf

Now I have one problem. If the line does not exist, I want to add it to the bottom of the file.

I am calling this with a `popen` out of a C program. I tried using `awk`.

How to add a line in sed if not match is found

I am using the following <code>sed</code> command to replace some parameters in a config file:
<pre><code class="hljs language-bash">sed -i 's/^option.*/option=value/g' /etc/fdm_monitor.conf
</code></pre>
Now I have one problem. If the line does not exist, I want to add it to the bottom of the file.
I am calling this with a <code>popen</code> out of a C program. I tried using <code>awk</code>.

How can I highlight the Bash/shell commands in Markdown files?

---

For example, to highlight `js`, I write:

&lt;!-- language: lang-none --&gt;

    ```js
    function () { return &quot;This code is highlighted as Javascript!&quot;}
    ```

To highlight HTML code I use ` ```html `.

How can we highlight Bash/shell commands?





Highlight Bash/shell code in Markdown files

sorry if this is a noobie question but I can&#39;t find a good answer.

To find then remove something I can use
 
    find . -name &quot;.txt&quot; -exec rm &quot;{}&quot; \;

But why can&#39;t I just pipe the results to rm like 

    find . -name &quot;.txt&quot; | rm 

like I would pipe it to grep
 
    find . -name &quot;.txt&quot; | grep a

I&#39;ve read from somewhere that rm doesn&#39;t take input from stdin and therefore I can&#39;t pipe it but what does that mean? When I type in rm a.txt it reads from standard input just like I can grep right? Or is there a difference between stdin and command line. Help!



Linux why can&#39;t I pipe find result to rm?

Now I want to find whether there are lines containing &#39;\&#39; character. I tried `grep &quot;\\&quot; XXFile` but it hints &quot;Trailing Backslash&quot;. But when I tried `grep &#39;\\&#39; XXFile` it is OK. Could anyone explain why the first case cannot run? Thanks.

When grep &quot;\\&quot; XXFile I got &quot;Trailing Backslash&quot;

If I have a file with rows like this

    /some/random/file.csv:some string
    /some/random/file2.csv:some string2

Is there some way to get a file that only has the first part before the colon, e.g.

    /some/random/file.csv
    /some/random/file2.csv

I would prefer to just use a bash one liner, but perl or python is also ok. 

bash, extract string before a colon

I&#39;m trying to collect information from a system and I need to get the current time in hours and minutes.

  Currently I have:

    date | awk &#39;{print $4}&#39;

which outputs something like:

    16:18:54

How do I chop off the seconds?

Get current time in hours and minutes

I would like to quickly monitor some hosts using commands like ps,dstat etc using ansible-playbook. The `ansible` command itself perfectly does what I want, for instance I&#39;d use:

    ansible -m shell -a &quot;ps -eo pcpu,user,args | sort -r -k1 | head -n5&quot;

and it nicely prints all std output for every host like this:

    localhost | success | rc=0 &gt;&gt;
    0.0 root     /sbin/init
    0.0 root     [kthreadd]
    0.0 root     [ksoftirqd/0]
    0.0 root     [migration/0]

    otherhost | success | rc=0 &gt;&gt;
    0.0 root     /sbin/init
    0.0 root     [kthreadd]
    0.0 root     [ksoftirqd/0]
    0.0 root     [migration/0] 

However this requires me to keep a bunch of shell scripts around for every task which is not very &#39;ansible&#39; so I put this in a playbook:

    ---
    -
      hosts: all
      gather_facts: no
      tasks:
        - shell: ps -eo pcpu,user,args | sort -r -k1 | head -n5

and run it with `-vv`, but the output baiscally shows the dictionary content and newlines are not printed as such so this results in an unreadable mess like this:

    changed: [localhost] =&gt; {&quot;changed&quot;: true, &quot;cmd&quot;: &quot;ps -eo pcpu,user,args | sort -r -k1 
    head -n5 &quot;, &quot;delta&quot;: &quot;0:00:00.015337&quot;, &quot;end&quot;: &quot;2013-12-13 10:57:25.680708&quot;, &quot;rc&quot;: 0,
    &quot;start&quot;: &quot;2013-12-13 10:57:25.665371&quot;, &quot;stderr&quot;: &quot;&quot;, &quot;stdout&quot;: &quot;47.3 xxx    Xvnc4 :24
    -desktop xxx:24 (xxx) -auth /home/xxx/.Xauthority -geometry 1920x1200\n
    .... 

 I also tried adding `register: var` and the a &#39;debug&#39; task to show `{{ var.stdout }}` but the result is of course the same.

Is there a way to get nicely formatted output from a command&#39;s stdout/stderr when run via a playbook? I can think of a number of possible ways (format output using sed? redirect output to file on the host then get that file back and echo it to the screen?), but with my limited knowledge of the shell/ansible it would take me a day to just try it out.


Ansible playbook shell output

**What I need:**

Suppose I have two commands, `A` and `B`, each of which returns a single-line string (i.e., a string with no newline character, except possibly 1 at the very end).  I need a command (or sequence of piped commands) `C` that concatenates the output of commands `A` and `B` on the same line and inserts 1 space character between them.  

**Example of how it should work:**

For example, suppose the output of command `A` is the string *between* the quotation marks here:

    &quot;The quick&quot;

And suppose the output of command `B` is the string *between* the quotation marks here:

    &quot;brown fox&quot;

Then I want the output of command(s) `C` to be the string *between* the quotation marks here:

    &quot;The quick brown fox&quot;

**My best attempted solution:**

In trying to figure out `C` by myself, it seemed that the follow sequence of piped commands should work:

    { echo &quot;The quick&quot; ; echo &quot;brown fox&quot; ; } | xargs -I{} echo {} | sed &#39;s/\n//&#39;

Unfortunately, the output of this command is
    
    The quick
    brown fox

Concatenate in bash the output of two commands without newline character

I&#39;m trying to replace `/./` or `/././` or `/./././` to `/` only in bash script. I&#39;ve managed to create regex for sed but it doesn&#39;t work.

    variable=&quot;something/./././&quot;
    variable=$(echo $variable | sed &quot;s/\/(\.\/)+/\//g&quot;)
    echo $variable # this should output &quot;something/&quot;

When I tried to replace only `/./` substring it worked with regex in sed `\/\.\/`. Does sed regex requires more flags to use multiplication of substring with `+` or `*`?

sed plus sign doesn&#39;t work

I want to insert multiple lines into a file using shell script.
Let us consider my input file contents are:
**input.txt:**

    abcd
    accd
    cdef
    line
    web

Now I have to insert four lines after the line &#39;cdef&#39; in the **input.txt** file.
After inserting my file should change like this:

    abcd
    accd
    cdef
    line1
    line2
    line3
    line4
    line
    web

The above insertion I should do using the shell script. Can any one help me?



How to add a line in sed if not match is found

Bash Problem Overview

Bash Solutions

How references to variables are resolved in Python

IndexError: tuple index out of range ----- Python

Attributions