Cutplace is a tool and API to validate that tabular data stored in CSV, Excel, ODS and PRN files conform to a cutplace interface definition (CID).
As an example, consider the following customers.csv
file that stores data about customers:
customer_id,surname,first_name,born,gender
1,Beck,Tyler,1995-11-15,male
2,Gibson,Martin,1969-08-18,male
3,Hopkins,Chester,1982-12-19,male
4,Lopez,Tyler,1930-10-13,male
5,James,Ana,1943-08-10,female
6,Martin,Jon,1932-09-27,male
7,Knight,Carolyn,1977-05-25,female
8,Rose,Tammy,2004-01-12,female
9,Gutierrez,Reginald,2010-05-18,male
10,Phillips,Pauline,1960-11-09,female
A CID can describe such a file in an easy to read way. It consists of three sections. First, there is the general data format:
.. | Property | Value |
---|---|---|
D | Format | Delimited |
D | Encoding | UTF-8 |
D | Header | 1 |
D | Line delimiter | LF |
D | Item delimiter | , |
Next there are the fields stored in the data file:
.. | Name | Example | Empty | Length | Type | Rule |
---|---|---|---|---|---|---|
F F F F F |
customer_id surname first_name date_of_birth gender |
3798 Miller John 1978-11-27 male |
X X |
...60 ...60 |
Integer DateTime Choice |
0...99999 YYYY-MM-DD female, male |
Optionally you can describe conditions that must be met across the whole file:
.. | Description | Type | Rule |
---|---|---|---|
C | customer must be unique | IsUnique | customer_id |
The CID can be stored in common spreadsheet formats, in particular Excel and ODS, for example cid_customers.ods
.
Cutplace can validate that the data file conforms to the CID:
$ cutplace cid_customers.ods customers.csv
Now add a new line with a broken date_of_birth
:
73921,Harris,Diana,04.08.1953,female
Cutplace rejects this file with the error message:
customers.csv (R12C4): cannot accept field 'date_of_birth': date must match format YYYY-MM-DD (%Y-%m-%d) but is: '04.08.1953'
Additionally, cutplace provides an easy to use API to read and write tabular data files using a common interface without having to deal with the intrinsic of data format specific modules. To read and validate the above example:
import cutplace
import cutplace.errors
cid_path = 'cid_customers.ods'
data_path = 'customers.csv'
try:
for row in cutplace.rows(cid_path, data_path):
pass # We could also do something useful with the data in ``row`` here.
except cutplace.errors.DataError as error:
print(error)
For more information, read the documentation at http://cutplace.readthedocs.org/ or visit the project at https://github.com/roskakori/cutplace.