Dump RRD XML to CSV

rrdxml.py

#!/usr/bin/env python
"""Export CSV from an RRD XML dump.

Usage: rrdxml.py file.xml rra

Where rra is the 0-based index for the RRA you want to dump.

"""
from csv import writer
from itertools import chain, izip
from lxml.etree import parse
from sys import argv, stdout


def comment_content(c):
    """Return the inner content from an XML comment. Strips surrounding
    whitespace.

    >>> comment_content("<!-- Yay! -->")
    'Yay!'

    """
    content = str(c)[4:-3]
    return content.strip()


def get_ts(c):
    """Return the unix timestamp component of an RRD XML date comment.

    >>> get_ts("<!-- 2011-04-28 19:18:40 BST / 1304014720 -->")
    '1304014720'

    """
    date, tstamp = comment_content(c).split("/")
    return tstamp.strip()


def iunshift(i1, i2):
    """Take one iterator of values and one iterator of iterators and return an
    iterator of iterators with the values prepended.

    >>> l = iunshift([1, 2, 3], [[2, 3], [3, 4], [4, 5]])
    >>> [list(e) for e in l]
    [[1, 2, 3], [2, 3, 4], [3, 4, 5]]

    """
    for x in izip(i1, i2):
        yield chain([x[0]], x[1])


def headers(tree):
    return (s.strip() for s in tree.xpath("//ds/name/text()"))


def values(tree, rra_index):
    row_nodes = tree.xpath("//rra[%s]/database/row" % rra_index)
    for rn in row_nodes:
        yield (v.text for v in rn)


def timestamps(tree, rra_index):
    """Extract timestamps from comments."""
    timestamp_nodes = tree.xpath("//rra[%s]/database/comment()" % rra_index)
    return (get_ts(c) for c in timestamp_nodes)


def rows(tree, rra_index):
    return iunshift(timestamps(tree, rra_index), values(tree, rra_index))


def dump(f, rra):
    """Dump RRA to list of lists."""
    tree = parse(f)
    yield headers(tree)
    for row in rows(tree, rra + 1):
        yield row


def dump_csv(f, rra, out):
    """Dump RRA to CSV (written to file object out)."""
    w = writer(out)
    for row in dump(f, rra):
        w.writerow([s.strip() for s in row])


if __name__ == "__main__":
    dump_csv(argv[1], int(argv[2]), stdout)

Can you please give me python script so that i can export data from munin graphs? I am not able to understand this as i am a newbee to munin.I am not able to understand that how can we get data from munin graphs.

I like this code thanks but I think I need the comments that are in every row in the XML as well as the values so I can use the data to create a line graph against time.

e..g
<!-- 2019-06-20 09:30:00 IST / 1561019400 --> 3.5280322222e+04 0.0000000000e+00 0.0000000000e+00
3.5572820556e+04 0.0000000000e+00 0.0000000000e+00

@scmgre No you don't need the comments. You can (indeed should) calculate the timestamps yourself. rrd.step is the basic time unit, rrd.lastupdate the time base. The row's time is thus rrd.lastupdate - (rrd.lastupdate % rrd.sep) - rra.pdp_per_row * rrd.step * (num_rows-row_nr).