weight.json

{
    "user": {
        "height": 1.75,
        "target_kg": 70,
        "target_date": "2017-08-01",
        "old": 25
    },
    "activity": {
        "2017-06-03": {
            "カロリー": {
                "昼": {
                    "チキンクリスプ": {
                        "kcal": 350,
                        "num": 2
                    }
                },
                "夜": {
                    "天下一品": 1000,
                    "アジフライ": 176,
                    "米": 100
                },
                "自転車": -2400
            },
            "体重": 78.4,
            "体脂肪率": 25.4
        },
        "2017-06-04": {
            "カロリー": {
                "昼": {
                    "アジの開き": 166,
                    "米": 284,
                    "味噌汁": 25
                },
                "夜": {
                    "生どら焼き": 290,
                    "ロースステーキ": 800,
                    "小松菜": {
                        "kcal": 6,
                        "num": 2
                    },
                    "味噌汁": 25
                },
                "自転車": -600
            },
            "体重": 78.7,
            "体脂肪率": 24.9
        }
    }
}

weight.py

from datetime import datetime
import json

json_dict = json.load(open("weight.json", "r"))
user = json_dict["user"]
dataset = json_dict["activity"]

kcal_kg = 7200                     # 出典 http://www.tanita.co.jp/health/detail/28
std_kg = 22 * user["height"]**2    # BMI22を元にした標準体重 (67.4kg)
target_kg = user["target_kg"]      # 目標の体重
target_date = user["target_date"]  # 目標の期限


def bmr(kg):
    # ハリスベネディクト基礎代謝 http://www.kintore.info/kisotaisya_mass/
    return 66.5 + kg * 13.8 + user["height"] * 500.0 - user["old"] * 6.8


def bmi(kg):
    return kg / user["height"]**2


def accumulate_kcal(data):
    if set(["num", "kcal"]) <= data.keys():
        return data["num"] * data["kcal"]

    result = 0.0
    for k, v in data.items():
        if isinstance(v, (int, float)):
            result += v
        elif isinstance(v, dict):
            result += accumulate_kcal(v)
    return result


def remained_days(d1):
    fmt = "%Y-%m-%d"
    if isinstance(d1, str):
        d1 = datetime.strptime(d1, fmt)
    d2 = datetime.strptime(target_date, fmt)
    return (d2 - d1).days


values = {}
def append(key, x):
    if key not in values.keys():
        values[key] = [x]
    else:
        values[key].append(x)


print("""
標準体重: {} kg
目標体重: {} kg
期限 {} (残り{}日)
""".format(std_kg, target_kg, target_date, remained_days(datetime.today())))


index = []
for date, data in dataset.items():
    actual_kg = data["体重"]
    remained_kcal = (actual_kg - target_kg) * kcal_kg
    index.append(date)
    base_kcal = bmr(actual_kg)
    actual_kcal = accumulate_kcal(data["カロリー"]) - base_kcal
    append("消費カロリー(kcal)", actual_kcal)
    append("残カロリー(kcal)", remained_kcal)
    append("目標消費カロリー(kcal)", - remained_kcal / remained_days(date))
    append("体重(kg)", actual_kg)
    append("予想体重(kg)", actual_kg + actual_kcal / kcal_kg)
    append("BMI", bmi(actual_kg))
    append("BMR", base_kcal)


# 表を出力
import pandas
from tabulate import tabulate
df = pandas.DataFrame(values, index=index)
print(tabulate(df, headers='keys', tablefmt='psql'))


# グラフを描画
import matplotlib
import matplotlib.pyplot as plt
import matplotlib.font_manager as fm
import matplotlib.dates as mdates
plt.style.use('ggplot')
# フリーフォントの Ricty を使用: https://github.com/mzyy94/RictyDiminished-for-Powerline
font_path = next(filter(lambda f: "Ricty" in f, fm.findSystemFonts()))
font_prop = fm.FontProperties(fname=font_path)
matplotlib.rcParams['font.family'] = font_prop.get_name()

df[["残カロリー(kcal)", "体重(kg)"]].plot(subplots=True)
plt.savefig("weight.svg")
print("グラフを weight.svg に保存しました")