Data wrangling in practice

Are you going to play with data?  First, you have to wrangle data, prepare it and make useful.  Having practice session Wrangling Subway Data in udacity course was nice way to use my knowledge in practice.  Subway data is a good sample of dataset consisting of several columns in CSV file.

Using dataset I was told to do:

some grouping

You can query Pandas dataset using SQL

Any SQL-compatible query can be applied.

merge files

Joining files together is as easy as iterating them and lines

shift and modify dataset

Dataframe was modified because I was told to calculate difference of values in following rows.

Creating new column with „ones” can be done as easy as df['newcolumn'] = 1