Two new functions for grass.script python lib

[sbl]

If you agree, I would like to add two new functions to grass.script python library, that I could not find in existing lib and that I would like to use in other module(s):

1. A function that parses a GRASS shell command (e.g. from history) into a dictionary that can be used in pygrass modules:

​https://trac.osgeo.org/grass/browser/sandbox/sbl/t.rast.aggregate.update/t.rast.aggregate.update.py#L67

2: A very basic function, that generates a random name for GRASS maps that are SQL and GRASS compliant: ​https://trac.osgeo.org/grass/browser/sandbox/sbl/t.rast.aggregate.update/t.rast.aggregate.update.py#L116

Docstrings would have to be improved, probably, and I am of course open to changing names or any other suggestions... If someone can point me to existing functions that do this which I overlooked, I am happy to use those instead...

[sbl]

OK, I found: https://grass.osgeo.org/grass74/manuals/libpython/script.html#script.task.cmdstring_to_tuple so that one is fine.

The only remaining thing would then be to add a script.core.tempname() function somewhere here I suppose: https://grass.osgeo.org/grass75/manuals/libpython/script.html#script.core.tempdir

My function below would require additional imports though, hope that would be OK... Generated names are SQL and GRASS mp name compliant.

import string
import random

def tempname(length, lowercase=False):
    """Generate a random name of length "length" starting with a letter

    :param int length: length of the random name to generate
    :param bool lowercase: use only lowercase characters to generate name
    :returns: String with a random name of length "length" starting with a letter
    :rtype: str

    :Example:

    >>> tempname(12)
    'MxMa1kAS13s9'
    """

    if lowercase:
        chars = string.ascii_lowercase + string.digits
    else:
        chars = string.ascii_uppercase + string.ascii_lowercase + string.digits
    randomname = '1'
    while randomname[0].isdigit():
        randomname = ''.join(random.choice(chars) for _ in range(length))

    return randomname

[sbl]

Since I did not hear any objections, I will commit this function to trunk preferably before 7.6 branch is cut. So I can use it in some addons that I have in progress...

[sbl]

In 73205:

add tempname() function to grass.script.core, fix #3615