Statistical Algorithms Importer: Python Project FAQ

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F.A.Q. of Statistical Algorithms Importer (SAI), here are common mistakes we have found in Python Project.

How to use the enumerated parameters

For example we consider this parameter:
Enumerated Param, SAI
As you can see, it is a Enumerated parameter and it is specified using a pipe-separated list of strings. The parameter will be transformed into a controlled vocabulary and will be displayed via a drop-down list in DataMiner.
Enumerated Param in DataMiner, SAI

How to use the input and output file parameters

For example we consider Phonebook algorithm:
Phonebook, SAI
Phonebook, SAI
Phonebook, SAI


DataMiner show the Phonebook algorithm in this way:
Phonebook in DataMiner interface, SAI


Python script code in sample:
#
# author Giancarlo Panichi
#
# Phonebook
# 
import sys
import string
 
def print_numbers(numbers):
    print "Telephone Numbers:"
    for x in numbers.keys():
        value="Name: "+x+" Number: "+numbers[x]
        print value,
 
def lookup_number(numbers,name):
    if numbers.has_key(name):
        return "For "+name+" the number is "+numbers[name]
    else:
        return "For "+name+" was not found"
 
def load_numbers(numbers,filename):
    with open(filename,"r") as f:
        for in_line in f:            
            [name,number] = string.split(in_line,",")
            numbers[name] = number
 
def save_result(result,filename):
    with open(filename,"w") as f:
        f.write(result)
 
phonebookFile=sys.argv[1] 
name=sys.argv[2]
phone_list = {}
 
load_numbers(phone_list,phonebookFile)
print_numbers(phone_list)
number=lookup_number(phone_list,name)
print number
save_result(number,"result.txt")


phonebook.csv:
Giancarlo,0123456789
Gianpaolo,9876541234
Paolo,1231410414


phonebook result with Giancarlo:
For Giancarlo the number is 0123456789


Phonebook code:

File:Phonebook.zip

Matplotlib

Matplotlib require the $DISPLAY environment variable which means a running X server. DataMiner service do not allow a running X server session. So your code must be modified:

#
# author Giancarlo Panichi
#
# Write file image.png
# 
import matplotlib as mpl
mpl.use('Agg')
import matplotlib.pyplot as plt
import numpy as np
....
plt.imshow(image)
plt.savefig('image.png')

Urllib

On DataMiner services is installed Urllib3, see:

#
# author Giancarlo Panichi
#
# Request Url
# 
import urllib3
http = urllib3.PoolManager()
r = http.request('GET', 'http://httpbin.org/robots.txt')
 
print(r.status)
print(r.data)


StorageHub

StorageHub is the service for accessing to the user's D4Science Workspace. Below we show the StorageHubFacilityPython algorithm, it exhibits the interactions with StorageHub through its Rest API:
StorageHub Facility Python, SAI
Indicates the I/O parameters:
StorageHub Facility Python I/O parameters, SAI
Indicates the python version:
StorageHub Facility Python version, SAI
Indicates the main code python:
StorageHub Facility Python Code, SAI


DataMiner result:
StorageHub Facility Python in DataMiner, SAI
This algorithm shows 5 types of interactions with StorageHub:
  • Get Root Info
  • Get Item Info (requires an itemId as argument1)
  • Get Root Children
  • Get Item Children (requires an itemId as argument1)
  • Item Download (requires an itemId as argument1)
Python source code of StorageHubFacilityPython:
File:StorageHubFacilityPython.zip
View the demo in DataMiner:
StorageHub Facility Python