Question: I have a python source block that gets the number of variables (columns) and cases in a pandas' dataframe.

Minimal example:

```
#+begin_src python :exports none :session :results output
  df = pd.DataFrame({'a': [1, 2, 3],
                     'b': [4, 5, 6]})
  df_len_columns = len(df.columns)
  df_len_cases = len(df.index)
#+end_src

```

What I would like to do now is use the value of those variables in inline source code like this:

The number of variables is `src_python{df_len_columns}` and the number of cases is `src_python{df_len_cases}`.

But this throws the following error: 

```
NameError: name 'df_len_columns' is not defined

```

Notice that I'm using the session argument `:session` thinking that it would be part of the same session and that it would work. I also search online extensively but couldn't find a solution to this particular question (most questions are about inline code for tables and inline code formatting).

Is there anyway to actually use these variables inline?

Answer: 
It looks like you need to tell the inline source code to refer to your session using a header argument:

```
src_python[:session]{df_len_columns}

```

The general form is `src_<language>[<header arguments>]{<body>}`. Possible header arguments are listed in the org manual: [Specific Header Arguments](https://orgmode.org/manual/Specific-header-arguments.html#Specific-header-arguments). 

Note: The value is substituted when the org file is exported via `org-export-dispatch`.
If I understood correctly you want to link several source blocks to the same process.

**It is as simple as:**

```
#+BEGIN_SRC ipython :results output :session testing
a = 5
#+END_SRC

#+RESULTS:

#+BEGIN_SRC ipython :results value  :session testing
a
#+END_SRC

#+RESULTS:
: # Out[6]:
: : 5

```

In this example the two source blocks are linked.

You can also tangle all the source blocks into one `.py` file.
using `M-x org-babel-tangle-file`, Every time you run that command the file will update with the new tangle.