Notebook Catenation

cat catenates the cells of multiple notebooks into a single notebook. The resulting notebook takes its notebook-level properties from the first notebook.

This tool can be used to prepend and append cells to a notebook (also see the append-cell option of the run tool). Prepended cells can provide (re)definitions, and appended cells can show further output.

Educational Use

In an educational setting, it can be useful to redefine the built-in function input() to either be blocked:

def input(*args, **kwargs):
    import sys
    print('input() is forbidden in notebooks', file=sys.stderr)
    sys.exit(1)

Or to deliver strings read from a file:

def __yield_from_file(file_name):
    with open(file_name) as f:
        yield from f.readlines()

def input(prompt=None, __gen=__yield_from_file('input.txt')):
    if prompt:
        print(prompt, end='')
    line = next(__gen)
    # suppress terminating end-of-line
    if line and line[-1] == '\n':
        return line[:-1]
    return line

By putting this code in a notebook, it can be prepended to every student notebook, via cat.

Result File Name

The result of catenating notebooks nb.ipynb ... is written to nb-cat.ipynb (that is, the name of the first notebook argument is used), unless the option --inplace is applied, in which case the result is written to nb.ipynb.

The result name addition can be adjusted in the configuration file by setting cat_result_name; see Configuration Files.

Options

cat does not have any tool-specific options.

JSON Output

See Write JSON Output for general information about JSON output.

cat produces the following members in the JSON output:

Name	Value
"cell_types"	object with counts per cell type (see Notebook Statistics)

Note that members are absent when count is zero.