如何使用 for 循环将不同的变量分配给 class object？

Question

I want to use a for loop to make the code shorter. In the following code I'm trying to create a chain of particles with same mass. Lets' say I want to create 50 particle. " system.addParticle(mass)" will add one particle. So basically to need 50 particles I have to repeat this 50 times. Is there any way to use for loop for that?

from simtk.openmm.app import *
from simtk.openmm import *
from simtk.unit import *
import numpy as np

mass = 1.0
system = System()
# This will add one particle
system.addParticle(mass)

Answer 1

I think this is equivalent:

from simtk.openmm.app import *
from simtk.openmm import *
from simtk.unit import *
import numpy as np

# Taken from https://docs.python.org/3/library/itertools.html#itertools-recipes
def pairwise(iterable):
    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
    a, b = tee(iterable)
    next(b, None)
    return zip(a, b)

new_pd = app.topology.Topology()

chain_new = new_pd.addChain()

residue_names = ['MET', 'THR', 'TYR', 'LYS', 'LEU']
residues = [new_pd.addResidue(name, chain_new) for name in residue_names]

atoms = [new_pd.addAtom('CA', 'C', res) for res in residues]

bonds = [new_pd.addBond(atom1, atom2) for atom1, atom2 in pairwise(atoms)]

Alternatively you could do something like:

def add_atom(topology, chain, residue_name):
    residue = new_pd.addResidue(residue_name, chain)
    atom = new_pd.addAtom('CA', 'C', residue)
    return atom

atoms = []
for residue_name in ['MET', 'THR', 'TYR', 'LYS', 'LEU']:
    atoms.append(add_atom(new_pd, chain_new, residue_name))
bonds = # ...