Improve plotting Timedelta on y-axis (Timedelta string representation)

Code Sample, a copy-pastable example if possible

Following https://github.com/pandas-dev/pandas/issues/9154#issuecomment-329814404 and https://github.com/pandas-dev/pandas/issues/16953#issuecomment-329905621

import pandas as pd
from pandas.compat import StringIO
import matplotlib.pyplot as plt


dat = """c1,c2,c3
1000,2000,1500
9000,8000,1600"""

df = pd.read_csv(StringIO(dat))

#print(df)

#df.plot.bar()
#plt.show()

df = df.apply(lambda x: pd.to_timedelta(x, unit='ms'))

print(df)

df.plot.bar()
plt.show()

Displays

        c1       c2              c3
0 00:00:01 00:00:02 00:00:01.500000
1 00:00:09 00:00:08 00:00:01.600000

Problem description

Y-axis should display Timedelta string representation (not integer values)

Expected Output

Output of pd.show_versions()

[paste the output of pd.show_versions() here below this line]

pd.show_versions()

INSTALLED VERSIONS

commit: 328c7e179b72e257e27adf92a06718fd5a40473f python: 3.6.2.final.0 python-bits: 64 OS: Darwin OS-release: 16.7.0 machine: x86_64 processor: i386 byteorder: little LC_ALL: None LANG: fr_FR.UTF-8 LOCALE: fr_FR.UTF-8

pandas: 0.21.0.dev+464.g328c7e179 pytest: 3.2.1 pip: 9.0.1 setuptools: 36.4.0 Cython: 0.26 numpy: 1.13.1 scipy: None pyarrow: None xarray: None IPython: None sphinx: None patsy: None dateutil: 2.6.1 pytz: 2017.2 blosc: None bottleneck: None tables: None numexpr: None feather: None matplotlib: 2.0.2 openpyxl: None xlrd: None xlwt: None xlsxwriter: None lxml: None bs4: None html5lib: None sqlalchemy: None pymysql: None psycopg2: None jinja2: None s3fs: None fastparquet: None pandas_gbq: None pandas_datareader: None

[1kastner]

@bzhphilou78 there are two workarounds:

1. Convert the timedelta into a floating point number of a given time unit, e.g. seconds/minutes/hours, depending on your problem. Just plot that.
2. Convert the pandas timedelta the numpy correspondent which is natively supported by matplotlib. Then you can use the different formatters that are shipped with matplotlib.

[StefanBrand]

Timedelta on y-axis still plots as milliseconds. 😬