====== Utilisation d'une "classe" pour des données de solvants chimiques ======

On peut utiliser la structure de classe pour créer une "table" de données sur des solvants. Il est alors possible d'effectuer des traitements de tris, sélection, impression...

<sxh  python; title : organic_solvents_data_class.py>
#!/usr/bin/env python 
# -*- coding: utf-8 -*-

# a solvent database using a list of class instances
# a modification of: http://www.daniweb.com/code/snippet390.html
# EU tested with Python 2.4   10/30/2006
#
# modification UMONS - cours programmation python - 2007-2012
#
 
import operator  # for attrgetter()
 
class Solvent(object):
    """a structure class for solvents, self refers to the instance"""
    def __init__(self, name=9999, bp=9999, mp=9999, fp=9999, dy=9999, de=9999, nr=9999, mu=9999, so=9999, fo=9999):
        self.name = name
        # 9999 --> not applicable
        self.bp = bp     # boiling point degC
        self.mp = mp     # melting point degC
        self.fp = fp     # flash point degC
        self.dy = dy     # density g/ml
        self.de = de     # dielectric constant
        self.nr = nr     # refractive index
        self.mu = mu     # dipole moment in Debye
        self.so = so     # solubility in water (g/100g water) --> 9000 = miscible
        self.fo = fo     # chemical formula

def table(solvent_list):
    """print a table of all solvent attributes"""
    title_str = "%-20s  %8s  %8s  %8s  %8s  %8s  %8s  %8s  %8s  %20s"
    data_str  = "%-20s  %8.1f  %8.1f  %8.1f  %8.3f  %8.2f  %8.2f  %8.2f  %8.2f  %-20s"
    print "-"*122
    print title_str % ("Name", "Bp", "Mp", "Fp", "Density", "Dielect", "Ref. Ind", "Dipole", "H2O Sol.", "Formula")
    for solvent in solvent_list:
        print data_str % (solvent.name, solvent.bp, solvent.mp, solvent.fp, solvent.dy, solvent.de, solvent.nr, solvent.mu, solvent.so, solvent.fo)
    print "-"*122
    print "9999 --> not applicable; 9000 --> miscible"
    print
 
def table_bp(solvent_list, bp_limit):
    """print a table of all solvent attributes, with bp restrictions"""
    title_str = "%-20s  %8s  %8s  %8s  %8s  %8s"
    data_str  = "%-20s  %8.1f  %8.1f  %8.1f  %8.3f    %8.2f"
    print "-"*72
    print title_str % ("Name", "Bp", "Mp", "Fp", "Density", "Dielectric")
    for solvent in solvent_list:
        if solvent.bp > bp_limit:
            print data_str % (solvent.name, solvent.bp, solvent.mp, solvent.fp, solvent.dy, solvent.de)
    print "-"*72
    print "9999 --> not applicable; 9000 --> miscible"
    print
    
# make a list of class Solvent instances
# also adds all the data/information
# data order = name, boiling point, melting point, flash point, density, dielectric constant,
# refractive index, dipole moment in Debye, solubility in water (g/100g water), chemical formula
# 9999 --> not applicable; 9000 --> miscible
solvent_list = []
solvent_list.append(Solvent("methanol", 64.7, -97.7, 11, 0.791, 32.7, 1.3284, 1.7, 9900, "CH4O"))
solvent_list.append(Solvent("ethanol", 78.3, -114.1, 8, 0.789, 24.55, 1.3614, 1.69, 9900, "C2H6O"))
solvent_list.append(Solvent("propanol iso", 82.3, -88, 22, 0.785, 19.92, 1.3772, 1.66, 9900, "C3H8O"))
solvent_list.append(Solvent("butanol normal", 117.7, -88.6, 35, 0.81, 17.51, 9999, 9999, 7.7, "C4H10O"))
solvent_list.append(Solvent("butanol secondary", 88.8, -114.7, 26, 0.805, 16.56, 9999, 9999, 9999, "C4H10O"))
solvent_list.append(Solvent("butanol tertiary", 82.2, 25.5, 4, 0.786, 10.9, 1.3877, 1.66, 9900, "C4H10O"))
#solvent_list.append(Solvent("benzyl alcohol", 205.4, -15.3, 100, 1.045, 13.1, 9999, 9999, 9999, "unknown"))
solvent_list.append(Solvent("acetone", 56.3, -94.7, -17, 0.791, 20.7, 1.3587, 2.85, 9900, "C3H6O"))
solvent_list.append(Solvent("toluene", 110.6, -94.9, 4, 0.867, 2.38, 1.4969, 0.43, 0.05, "C7H8"))
solvent_list.append(Solvent("water", 100, 0, 9999, 1, 78.5, 1.333, 1.82, 9900, "H2O"))
solvent_list.append(Solvent("dimethyl formamide", 153, -61, 58, 0.944, 36.7, 1.4305, 3.86, 9900, "C3H7NO"))
solvent_list.append(Solvent("acetic acid", 118, 17, 39, 1.049, 6.15, 1.3716, 1.68, 9900, "C2H4O2"))
# got the drift, add more solvents here ...
 
 
print "Sort the solvent_list by name ..."
solvent_list.sort(key=operator.attrgetter('name'))
# ... now show a table of the solvent_list
table(solvent_list)
 
print
 
print "Sort the solvent_list by melting point ..."
solvent_list.sort(key=operator.attrgetter('mp'))
# ... now show a table of the solvent_list
table(solvent_list)
 
print
 
print "Sort the solvent_list by boiling point ..."
solvent_list.sort(key=operator.attrgetter('bp'))
# ... now show a table of the solvent_list
table(solvent_list)
 
print

# ajouter suivant d'autres tris (solubilité ,...)
 
bp_limit = 75
print "Show only solvents boiling higher than %0.1f degC:" % bp_limit
# show a boiling point restricted table
table_bp(solvent_list, bp_limit)

# on peut chercher un solvant de densité supérieure à l'eau, mais
# peu soluble ou insoluble (solubilité < 0.05 par exemple)


</sxh>