基于Matplotlib的图表库简单封装，方便绘制直方图、圆饼图、折线图、散点图和箱形图。

Chart.py

#!/usr/bin/env python3

# -- 非线程安全 --

from matplotlib.font_manager import FontProperties
from operator import itemgetter
from itertools import groupby
import matplotlib.pyplot as canvas
import numpy as np

# constants

DPI=100
CHINESE = FontProperties(fname = '/System/Library/Fonts/PingFang.ttc', size = 12)

# private utilities

def _get(values, index, default = None):
    return values[index] if 0 <= index < len(values) else default

# privates

def _initialize(width, height, font_size):
    global CHINESE, DPI
    CHINESE.set_size(font_size)
    canvas.clf()
    canvas.figure(figsize=(width / float(DPI), height / float(DPI)), dpi=DPI)

def _decorate(title, legend, axis):
    global CHINESE

    if title:
        canvas.title(title, fontproperties=CHINESE)

    if legend and 'position' in legend:
        canvas.legend(loc=legend['position'], prop=CHINESE)

    if axis:
        if 'x' in axis:
            if 'label' in axis['x']:
                canvas.xlabel(axis['x']['label'], fontproperties=CHINESE)
            if 'ticks' in axis['x'] and axis['x']['ticks']:
                ticks = axis['x']['ticks']
                canvas.xticks([tick['value'] for tick in ticks],
                              [tick.get('label', tick['value']) for tick in ticks],
                              fontproperties=CHINESE)
        if 'y' in axis:
            if 'label' in axis['y']:
                canvas.ylabel(axis['y']['label'], fontproperties=CHINESE)
            if 'ticks' in axis['y'] and axis['y']['ticks']:
                ticks = axis['y']['ticks']
                canvas.yticks([tick['value'] for tick in ticks],
                              [tick.get('label', tick['value']) for tick in ticks],
                              fontproperties=CHINESE)

def _save(to):
    global DPI
    canvas.savefig(to, dpi=DPI)

def _draw(fn, data, to, title, legend, axis, width, height, font_size):
    _initialize(width, height, font_size)

    if type(data) is list:
        for element in data:
            fn(element)
    else:
        fn(data)

    _decorate(title, legend, axis)
    _save(to)

# draw

def _bar(data):
    labels = data.get('labels', [data.get('label', '')])
    values = data['values']
    
    size = len(values)
    xs = np.linspace(0, size, size, endpoint=False)
    ys = [(e['y'] if type(e['y']) is list else [e['y']]) for e in values]

    times = max([len(y) for y in ys])
    width = data.get('width', 0.8) / float(times)

    for index in range(times):
        canvas.bar(xs + (0.1 + index * width),
                   [_get(y, index, 0) for y in ys],
                   label=_get(labels, index, ''),
                   width=width,
                   align='edge')

    ticks = [str(e['x']) for e in values]
    canvas.xticks(xs + 0.5, ticks, fontproperties=CHINESE)

def _box(data):
    global CHINESE
    get_x = itemgetter('x')
    values = groupby(sorted(data['values'], key=get_x), get_x)
    points = [(k, [v['y'] for v in vs]) for k, vs in values]
    canvas.boxplot([p[1] for p in points], showmeans=True)
    canvas.xticks(np.linspace(1, len(points), len(points)),
                  [p[0] for p in points],
                  fontproperties=CHINESE)

def _plot(data):
    canvas.plot([e['x'] for e in data['values']],
                [e['y'] for e in data['values']],
                label=data.get('label', ''),
                linestyle=data.get('style', '-'),
                linewidth=data.get('width', None),
                color=data.get('color', None))

def _scatter(data):
    canvas.scatter([e['x'] for e in data['values']],
                   [e['y'] for e in data['values']],
                   label=data.get('label', ''))

def _pie(data):
    global CHINESE
    values = sorted(data['values'], key=itemgetter('y'), reverse=True)
    canvas.pie([e['y'] for e in values],
               labels=[e['x'] for e in values],
               autopct='%3.2f%%',
               startangle=90,
               textprops={'fontproperties':CHINESE})

# exports

def bar(data, to, title=None, legend=None, axis=None, width=1600, height=1200, font_size=12):
    _draw(_bar, data, to, title, legend, axis, width, height, font_size)

def box(data, to, title=None, legend=None, axis=None, width=1600, height=1200, font_size=12):
    _draw(_box, data, to, title, legend, axis, width, height, font_size)

def plot(data, to, title=None, legend=None, axis=None, width=1600, height=1200, font_size=12):
    _draw(_plot, data, to, title, legend, axis, width, height, font_size)

def scatter(data, to, title=None, legend=None, axis=None, width=1600, height=1200, font_size=12):
    _draw(_scatter, data, to, title, legend, axis, width, height, font_size)

def pie(data, to, title=None, legend=None, axis=None, width=1600, height=1200, font_size=12):
    _draw(_pie, data, to, title, legend, axis, width, height, font_size)