python 调用 shell 命令，制作用户界面

1. python调用shell指令: os.system

格式为 os.system('command')

import os
os.system('make')
flag0 = flag[0]; flag1 = flag[1]; flag2 = flag[2]; flag3 = flag[3]; flag4 = flag[4]
os.system('echo %d %d %d %d %d > output/cin.massfit' % (flag0, flag1, flag2, flag3, flag4))
os.system('./massfit.x < output/cin.massfit')

如上，可以在 python 中命令 shell 编译其他 c++ 程序，然后运行该程序。值得注意的是上面的第 4 排，可以将 python 中的变量的值传给 shell。这样，可以用 python tinker 写一个用户界面，然后让用户在界面上点点点或者输入参数，再按某个键，底层的c++程序就去跑。我是这样给 c++ 程序添加界面的。

2. python 制作用户界面

tinker 模块可以制作简单的用户界面，我试过几个，录在这里

2.1 文本编辑器

# A simple text file editor

from tkinter import *
from tkinter.scrolledtext import ScrolledText

def load():
    with open(filename.get()) as file:
        contents.delete('1.0', END)
        contents.insert(INSERT, file.read())

def save():
    with open(filename.get(), 'w') as file:
        file.write(contents.get('1.0', END))

top = Tk()
top.resizable(False, False)
top.title("Simple Editor")

contents = ScrolledText()
contents.pack( side = BOTTOM, expand=True, fill=BOTH)

filename = Entry()
filename.pack(side=LEFT, expand=True, fill=X)

Button(text='Open', command=load).pack(side=LEFT)
Button(text='Save', command=save).pack(side=LEFT)

#ttk.Label(top, text="A Label").grid(column=0, row=0)

mainloop()

2.2 点击按键，文本改变

# click a button and a text changes

import tkinter as tk
from tkinter import ttk

win = tk.Tk()

win.title("Python GUI")

a_label = ttk.Label(win, text="A Label")
a_label.grid(column=0, row=0)

def click_me():
    action.configure(text="** I have been Clicked! **")
    a_label.configure(foreground='red')
    a_label.configure(text='A Red Label')
    
action = ttk.Button(win, text="Click Me!", command=click_me)
action.grid(column=1, row=0)

win.mainloop()

2.3 输入人名，自动打招呼

# Input a name and say hello to the person

import tkinter as tk
from tkinter import ttk

win = tk.Tk()

def click_me():
    action.configure(text='Hello ' + name.get())
    # the button click event is a callback function
ttk.Label(win, text="Enter a name:").grid(column=0, row=0)

action = ttk.Button(win, text="Click Me!", command=click_me)
action.grid(column=1, row=1)
action.configure(state='disabled') # Disable the Button Widget

name = tk.StringVar() # Note: tk.StringVar
name_entered = ttk.Entry(win, width=12, textvariable=name)
name_entered.grid(column=0, row=1)

name_entered.focus()

win.mainloop()

2.4 还有点问题的画图界面

import tkinter

from matplotlib.backends.backend_tkagg import (
    FigureCanvasTkAgg, NavigationToolbar2Tk)
# Implement the default Matplotlib key bindings.
from matplotlib.backend_bases import key_press_handler
from matplotlib.figure import Figure

import numpy as np


root = tkinter.Tk()
root.wm_title("Embedding in Tk")

fig = Figure(figsize=(5, 4), dpi=100)
t = np.arange(0, 3, .01)
fig.add_subplot(111).plot(t, 2 * np.sin(2 * np.pi * t))

canvas = FigureCanvasTkAgg(fig, master=root)  # A tk.DrawingArea.
canvas.draw()

# pack_toolbar=False will make it easier to use a layout manager later on.
toolbar = NavigationToolbar2Tk(canvas, root, pack_toolbar=False)
toolbar.update()

canvas.mpl_connect(
    "key_press_event", lambda event: print(f"you pressed {event.key}"))
canvas.mpl_connect("key_press_event", key_press_handler)

button = tkinter.Button(master=root, text="Quit", command=root.quit)

# Packing order is important. Widgets are processed sequentially and if there
# is no space left, because the window is too small, they are not displayed.
# The canvas is rather flexible in its size, so we pack it last which makes
# sure the UI controls are displayed as long as possible.
button.pack(side=tkinter.BOTTOM)
toolbar.pack(side=tkinter.BOTTOM, fill=tkinter.X)
canvas.get_tk_widget().pack(side=tkinter.TOP, fill=tkinter.BOTH, expand=1)

tkinter.mainloop()

2.5 最后是原子核质量液滴模型拟合界面，需要搭配我写的 c++ 拟合程序使用

#coding=utf-8
import os
# Liquid Drop Model, fit the AME2012 mass data with (optionally) these terms:
# volume, surface, symmetry, Coulumb, pairing
import matplotlib
matplotlib.use('TkAgg') # matplotlib 后端设置为　TkAgg，才能与 tkinter 一致
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg # 设置 canvas
from matplotlib.figure import Figure # 声明　Figure
from tkinter import *

root = Tk() # Tk 实例
root.title("Residual error of liquid drop model of nuclear masses") # title

f = Figure(figsize=(8,5), dpi=100)
fplot = f.add_subplot(111)

def _destroyWindow():
    root.quit()
    root.destroy()

color = ['#d9d9d9','green']; flag=[0,0,0,0,0]
def volume():
    flag[0] = ( flag[0]+1 )%2 # jump between 0,1
    button0.config(bg = color[flag[0]], activebackground=color[flag[0]])
def surface():
    flag[1] = ( flag[1]+1 )%2
    button1.config(bg = color[flag[1]], activebackground=color[flag[1]])
def symmetry():
    flag[2] = ( flag[2]+1 )%2
    button2.config(bg = color[flag[2]], activebackground=color[flag[2]])
def coulomb():
    flag[3] = ( flag[3]+1 )%2
    button3.config(bg = color[flag[3]], activebackground=color[flag[3]])
def pairing():
    flag[4] = ( flag[4]+1 )%2
    button4.config(bg = color[flag[4]], activebackground=color[flag[4]])
def cal_Bres():
    # run c++ code and get data
    os.system('make')
    flag0 = flag[0]; flag1 = flag[1]; flag2 = flag[2]; flag3 = flag[3]; flag4 = flag[4]
    os.system('echo %d %d %d %d %d > output/cin.massfit' % (flag0, flag1, flag2, flag3, flag4))
    os.system('./massfit.x < output/cin.massfit')
def draw_ZBres():
    cal_Bres()
    data = np.loadtxt("output/res.txt")
    Z = data[:,0]; N = data[:, 1]; A = data[:, 2]; Bres = data[:, 3]
    fplot.clear(); fplot.set_xlabel("Z"); fplot.set_ylabel("Bres = Bexp. - Bth. (MeV)")
    fplot.scatter(Z,Bres,s=1); canvs.draw()
def draw_NBres():
    cal_Bres()
    data = np.loadtxt("output/res.txt")
    Z = data[:,0]; N = data[:, 1]; A = data[:, 2]; Bres = data[:, 3]
    fplot.clear(); fplot.set_xlabel("Z"); fplot.set_ylabel("Bres = Bexp. - Bth. (MeV)")
    fplot.scatter(N,Bres,s=1); canvs.draw()

canvs = FigureCanvasTkAgg(f,root)
canvs.get_tk_widget().pack(side=TOP, fill=BOTH, expand=1)
button0 = Button(root, text='volume', command=volume); button0.pack(side=LEFT)
button1 = Button(root, text="surface", command=surface); button1.pack(side=LEFT)
button2 = Button(root, text="symmetry", command=symmetry); button2.pack(side=LEFT)
button3 = Button(root, text="coulomb", command=coulomb); button3.pack(side=LEFT)
button4 = Button(root, text="pairing", command=pairing); button4.pack(side=LEFT)
button_draw_ZBres = Button(root, text="Bres v.s. Z", command=draw_ZBres).pack(side=LEFT)
button_draw_ZBres = Button(root, text="Bres v.s. N", command=draw_NBres).pack(side=LEFT)

root.mainloop()