Tuesday, November 14, 2017

How to convert epoch time to datetime in Pandas


While i am working with iot data to transform UNIX epoch time in seconds. I would like to convert epoch time in seconds into human readable date time and not a reference date which is based upon 1970.

I have my data in pandas dataframe, below screen shot shows "createdTime" column in epoch time in seconds:

Here is the code segment that convert UNIX epoch time into date time:

convert = lambda x: datetime.datetime.fromtimestamp(x / 1e3)
ds['ts'] = ds['createdTime'].apply(convert)

This code generates the expected output, below screen shot shows the output:

Hope this helps!

Enable Jupyter notebook in Anaconda Navigator


After i installed the latest conda runtime (anaconda 3 x64 distro) that uses Anaconda 3 on Windows 64 bit.

When i try to click on a target environment, i see that "Open with IPython" or "Open with Jupyter Notebook"

The question is how to enable this? I found how to install Jupyter notebook package for conda environment where it would be accessible through the Navigator tool.

Follow below steps:

1) Select any of the available environment, Click on "Open terminal" window.
2) Type the following command:

conda install nb_conda

3) This will install notebook packages for Jupyter and once it is completed, The Jupyter notebook will be available for all environments.

4) To testify this work properly, Click on Jupyter link and this will open up the notebook.

5) Write some code to make sure this works with no issues.

import pandas as pd
s = pd.Series([1508258340299])

The code executed with no issues:

Hope this helps!

Thursday, November 09, 2017

Error downloading files from secure sites in .NET apps 4.6.2

Hi All,

I was working on upgrading a .Net application runtime from version 4.5 to latest one 4.6.2. After i did that, the application threw an error in the step of downloading a zip file from a secure site.

The app throws thew following error:

{"The request was aborted: Could not create SSL/TLS secure channel."} when trying to download file

The code snippet that was throwing the error in the DownloadFile method in .NET WebClient class:

C# code:

 using (WebClient wc = new WebClient())

                wc.DownloadFile(ssl_url, downloadedFilePath);

The destination is a secure site uses SSL, after searching and trying different options, I found out the solution by enabling the TLS 1.1 and TLS 2.2 before calling download file method.

Here is the modified code snippet:

 System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls11| SecurityProtocolType.Tls12;
            using (WebClient wc = new WebClient())
                wc.DownloadFile(nhtsa_url, downloadedFilePath);

Hope this helps!