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 “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 “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)
# 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>