【Tkinter】ウィジェット変数とは？StringVar含む4つを解説！

import tkinter as tk


root = tk.Tk()

string_var = tk.StringVar(
    root,  # 親ウィジェット
    "aaa",  # 初期値
    "string_var",  # 名前
)

import tkinter as tk

root = tk.Tk()
string_var = tk.StringVar(root)  # OK

frame = tk.Frame(root)
int_var = tk.IntVar(frame)  # OK

spinbox = tk.Spinbox(frame)
double_var = tk.DoubleVar(spinbox)  # OK

import tkinter as tk

root = tk.Tk()
string_var = tk.StringVar(root)
print(vars(string_var))
#　{'_root': <tkinter.Tk object .>, '_tk': <_tkinter.tkapp object at 0x102447630>, '_name': 'PY_VAR0'}

frame = tk.Frame(root)
int_var = tk.IntVar(frame)
print(vars(int_var))
# {'_root': <tkinter.Tk object .>, '_tk': <_tkinter.tkapp object at 0x102447630>, '_name': 'PY_VAR1'}

spinbox = tk.Spinbox(frame)
double_var = tk.DoubleVar(spinbox)
print(vars(double_var))
# {'_root': <tkinter.Tk object .>, '_tk': <_tkinter.tkapp object at 0x102447630>, '_name': 'PY_VAR2'}

import tkinter as tk

string_var = tk.StringVar()
# RuntimeError: Too early to create variable: no default root window

import tkinter as tk

root = tk.Tk()

string_var = tk.StringVar()

import tkinter as tk

entry = tk.Entry()

string_var = tk.StringVar()

import tkinter as tk

root = tk.Tk()

string_var = tk.StringVar(value="1")
int_var = tk.IntVar(value=1)
double_var = tk.DoubleVar(value=1.0)
boolean_var = tk.BooleanVar(value=True)

import tkinter as tk

root = tk.Tk()

string_var = tk.StringVar(value=1)
int_var = tk.IntVar(value=1)
double_var = tk.DoubleVar(value=1)
boolean_var = tk.BooleanVar(value=1)

import tkinter as tk

root = tk.Tk()

double_var = tk.DoubleVar(value="1.0")  # OK
print(double_var.get())
# 1.0

double_var = tk.DoubleVar(value="")  # NG
print(double_var.get())
# _tkinter.TclError: expected floating-point number but got ""

import tkinter as tk

root = tk.Tk()

string_var = tk.StringVar(name="named var")
print(string_var)
# named variable

import tkinter as tk

root = tk.Tk()

string_var = tk.StringVar()
print(string_var)
# PY_VAR0

int_var = tk.IntVar()
print(int_var)
# PY_VAR1

double_var = tk.DoubleVar()
print(double_var)
# PY_VAR2

import tkinter as tk

root = tk.Tk()

string_var = tk.StringVar(name="named var", value="Hello, World.")

# 名前を使って変数の値を取得
value = root.globalgetvar("named var")

print(value)
# Hello, World.

import tkinter as tk

root = tk.Tk()

string_var = tk.StringVar(value="Hello, World.")

# 変数の値を取得
value = string_var.get()

print(value)
# Hello, World.

import tkinter as tk

root = tk.Tk()

string_var = tk.StringVar(value=1)
string_value = string_var.get()
print(type(string_value), string_value)
# <class 'str'> 1

int_var = tk.IntVar(value=1)
int_value = int_var.get()
print(type(int_value), int_value)
# <class 'int'> 1

double_var = tk.DoubleVar(value=1)
double_value = double_var.get()
print(type(double_value), double_value)
# <class 'float'> 1.0

boolean_var = tk.BooleanVar(value=1)
boolean_value = boolean_var.get()
print(type(boolean_value), boolean_value)
# <class 'bool'> True

import tkinter as tk

root = tk.Tk()
string_var = tk.StringVar()

string_var.set("Hello, World.")
print(string_var.get())
# Hello, World.

string_var.set("Bonjour, le monde.")
print(string_var.get())
# Bonjour, le monde.

string_var.set("Hallo, Welt.")
print(string_var.get())
# Hallo, Welt.

variable.trace_add(("read" "write"), callback)

import tkinter as tk

def callback(*args):
    print("Callback triggered!")

root = tk.Tk()

# trace_add
string_var = tk.StringVar()
string_var.trace_add("write", callback)  # 確認したいmodeを指定

# 変数の値を読み取る
print("Before reading the value")
string_var.get()
print("After reading the value\n")

# 変数の値を変更
print("Before changing the value")
string_var.set("New Value")
print("After changing the value\n")

# 変数を削除
print("Before removing the variable")
del string_var  # または string_var = None
print("After removing the variable")

Before reading the value
After reading the value

Before changing the value
Callback triggered!
After changing the value

Before removing the variable
After removing the variable

Before reading the value
Callback triggered!
After reading the value

Before changing the value
After changing the value

Before removing the variable
Callback triggered!
After removing the variable

def callback(var_name, index, mode):

import tkinter as tk

def callback(var_name, index, mode):
    print(f"var_name: {var_name}")
    print(f"index: {index}")
    print(f"mode: {mode}")

root = tk.Tk()

string_var = tk.StringVar()
string_var.trace_add("write", callback)

string_var.set("Hello, World.")
# var_name: PY_VAR0
# index: 
# mode: write

def callback(*args):

variable.trace_add("write", lambda *args: 処理)

variable.trace_remove(["write" "unset"], cbname)

callback_id = variable.trace_add("write", lambda *args: None)
variable.trace_remove("read", callback_id)  # OK

import tkinter as tk

def callback(*args):
    print("Callback triggered!")

root = tk.Tk()

string_var = tk.StringVar()
callback_id = string_var.trace_add("write", callback)

print(type(callback_id), callback_id)
# <class 'str'> 4347542208callback

string_var.trace_remove("write", callback_id)

string_var.trace_remove("write", callback)
# TypeError: deletecommand() argument must be str, not function

import tkinter as tk

def callback1(*args):
    print("Callback1 triggered!")

def callback2(*args):
    print("Callback2 triggered!")

root = tk.Tk()
string_var = tk.StringVar()

string_var.trace_add(("write", "unset",), callback1)
string_var.trace_add("read", callback2)

info = string_var.trace_info()
print(info)
# [(('read',), '4334190144callback2'), (('write', 'unset'), '4334189952callback1')]

import tkinter as tk

# リストボックスの内容を検索語に基づいてフィルタリングする関数
def update_listbox(*args):
    search_term = search_var.get().lower()  # 検索語を小文字に変換
    filtered_items = [item for item in items if search_term in item.lower()]  # フィルタリング
    listbox.delete(0, tk.END)  # リストボックスをクリア
    for item in filtered_items:
        listbox.insert(tk.END, item)  # フィルタリングされた項目をリストボックスに追加

# ウィンドウの作成
root = tk.Tk()

# 適当な製品名リスト
items = [
    "Apple iPhone 13", "Samsung Galaxy S21", "Google Pixel 6", "Sony WH-1000XM4",
    "Bose QuietComfort 35", "Dell XPS 13", "Apple MacBook Pro", "Microsoft Surface Pro 7",
    "Amazon Echo Dot", "Google Nest Hub", "Roku Streaming Stick+", "Apple Watch Series 6",
    "Fitbit Charge 5", "Canon EOS R5", "Nikon Z6 II", "Sony Alpha 7C", "Panasonic Lumix GH5",
    "GoPro HERO9 Black", "DJI Mavic Air 2", "Samsung QLED TV", "LG OLED TV", "TCL Roku TV",
    "HP Envy x360", "Asus ROG Zephyrus", "Lenovo ThinkPad X1", "Acer Predator Helios 300",
    "Alienware m15", "Nintendo Switch", "Sony PlayStation 5", "Xbox Series X",
    "Apple AirPods Pro", "Samsung Galaxy Buds Pro", "Sony WF-1000XM4", "Jabra Elite 85t",
    "Anker Soundcore Liberty Air 2 Pro", "Logitech MX Master 3", "Razer DeathAdder V2",
    "Corsair K95 RGB Platinum", "SteelSeries Apex Pro", "HyperX Alloy Elite 2",
    "Netgear Nighthawk AX12", "TP-Link Archer AX6000", "Asus RT-AX88U", "Google Nest Wifi",
    "Eero Pro 6", "Ring Video Doorbell Pro", "Arlo Pro 4", "Wyze Cam v3",
    "Nest Learning Thermostat", "Ecobee SmartThermostat", "August Wi-Fi Smart Lock",
    "SimpliSafe Home Security System", "Philips Hue White and Color Ambiance",
    "LIFX A19 LED Light", "Sengled Smart LED Multicolor", "Nanoleaf Shapes",
    "Govee Immersion LED TV Backlights", "Dyson V11 Torque Drive", "Shark Navigator Lift-Away",
    "iRobot Roomba i7+", "Eufy RoboVac 11S", "Bissell CrossWave", "Black+Decker Dustbuster",
    "Instant Pot Duo", "Ninja Foodi", "Breville Smart Oven", "KitchenAid Stand Mixer",
    "Vitamix 5200", "Cuisinart Food Processor", "Nespresso VertuoPlus", "Keurig K-Elite",
    "Hamilton Beach FlexBrew", "Black+Decker 12-Cup Coffee Maker", "Whirlpool WRF535SMHZ",
    "LG LFXS26973S", "Samsung RF28R7351SG", "GE Profile PFE28KYNFS", "Bosch 800 Series SHXM78Z55N",
    "Miele Classic G4228SCU", "Frigidaire FGID2466QF", "Maytag MDB4949SHZ", "Dyson Supersonic",
    "Revlon One-Step Hair Dryer", "Conair InfinitiPro", "BaBylissPRO Nano Titanium",
    "Panasonic EH-NA65-K", "Remington Pro Pearl Ceramic", "Beats Solo Pro", "Marshall Major IV",
    "Bose SoundLink II", "JBL Flip 5", "Ultimate Ears WONDERBOOM 2", "Anker Soundcore Motion+",
]

# StringVarのインスタンス
search_var = tk.StringVar()
# search_varが変更されるたびにupdate_listbox関数を呼び出す
search_var.trace("w", update_listbox)

# 検索ボックス
search_entry = tk.Entry(root, textvariable=search_var, width=50)
search_entry.pack(pady=10)

# リストボックス
listbox = tk.Listbox(root, width=50, height=20)
listbox.pack(pady=10)
update_listbox()  # 初期表示

# メインループの開始
root.mainloop()

# search_varが変更されるたびにupdate_listbox関数を呼び出す
search_var.trace("w", update_listbox)

# 検索ボックス
search_entry = tk.Entry(root, textvariable=search_var, width=50)

def update_listbox(*args):
    """
    search_varが変更されるたびに呼び出される関数。
    リストボックスの内容を検索語に基づいてフィルタリングする。
    """
    search_term = search_var.get().lower()  # 検索語を小文字に変換
    filtered_items = [item for item in items if search_term in item.lower()]  # フィルタリング
    listbox.delete(0, tk.END)  # リストボックスをクリア
    for item in filtered_items:
        listbox.insert(tk.END, item)  # フィルタリングされた項目をリストボックスに追加

import tkinter as tk

def calculate():
    try:
        total = total_var.get()
    except:
        return None

    people = people_var.get()

    return total / people

def show_result(per_person):
    try:
        text = f"一人当たりの金額: {per_person:.2f}円"
    except:
        text = "エラー"

    result_label.config(text=text)

# ウィンドウの作成
root = tk.Tk()

# 合計金額の入力
total_label = tk.Label(root, text="合計金額 (円):")
total_label.grid(column=0, row=0, padx=5, pady=5)

total_var = tk.IntVar()
total_spinbox = tk.Spinbox(root, from_=0, to=100000, textvariable=total_var)
total_spinbox.grid(column=1, row=0, padx=5, pady=5)

# 人数の入力
people_label = tk.Label(root, text="人数 (人):")
people_label.grid(column=0, row=1, padx=5, pady=5)

people_var = tk.IntVar()
people_spinbox = tk.Spinbox(root, from_=1, to=100, textvariable=people_var, state="readonly")
people_spinbox.grid(column=1, row=1, padx=5, pady=5)

# 結果表示用のラベル
result_label = tk.Label(root, text="一人当たりの金額: ")
result_label.grid(column=0, row=2, columnspan=2, padx=5, pady=5)

# 計算ボタン
calc_button = tk.Button(root, text="計算", command=lambda: show_result(calculate()))
calc_button.grid(column=0, row=3, columnspan=2, padx=5, pady=5)

# メインループの開始
root.mainloop()

total_var = tk.IntVar()
total_spinbox = tk.Spinbox(root, from_=0, to=100000, textvariable=total_var)
total_spinbox.grid(column=1, row=0, padx=5, pady=5)

…

people_var = tk.IntVar()
people_spinbox = tk.Spinbox(root, from_=1, to=100, textvariable=people_var,  state=“readonly”)
people_spinbox.grid(column=1, row=1, padx=5, pady=5)

def calculate():
    try:
        total = total_var.get()
    except:
        return None

    people = people_var.get()

    return total / people

import tkinter as tk

# BMIを計算する関数
def calculate_bmi():
    weight = weight_var.get()
    height_cm = height_var.get()
    height_m = height_cm / 100  # cmをmに変換

    bmi = weight / (height_m ** 2)
    bmi_var.set(round(bmi, 2))

    if bmi < 18.5:
        category_var.set("低体重(痩せ)")
    elif 18.5 <= bmi < 25:
        category_var.set("普通体重")
    elif 25 <= bmi < 30:
        category_var.set("肥満(1度)")
    elif 30 <= bmi < 35:
        category_var.set("肥満(2度)")
    elif 35 <= bmi < 40:
        category_var.set("肥満(3度)")
    else:
        category_var.set("肥満(4度)")

# メインウィンドウの設定
root = tk.Tk()

# デフォルト値
default_height = 170.0  # cm
default_weight = 60.0  # kg

# DoubleVarオブジェクトの設定
height_var = tk.DoubleVar(value=default_height)
weight_var = tk.DoubleVar(value=default_weight)
bmi_var = tk.DoubleVar()
category_var = tk.StringVar()

# ウィジェットの配置
tk.Label(root, text="身長 (cm)").grid(row=1, column=0)
tk.Spinbox(root, from_=100, to=220, increment=0.1, textvariable=height_var, state="readonly").grid(row=0, column=1)

tk.Label(root, text="体重 (kg)").grid(row=0, column=0)
tk.Spinbox(root, from_=30, to=150, increment=0.1, textvariable=weight_var, state="readonly").grid(row=1, column=1)

tk.Button(root, text="BMI計算", command=calculate_bmi).grid(row=2, columnspan=2)

tk.Label(root, text="BMI").grid(row=3, column=0)
tk.Entry(root, textvariable=bmi_var, state='readonly').grid(row=3, column=1)

tk.Label(root, text="カテゴリー").grid(row=4, column=0)
tk.Entry(root, textvariable=category_var, state='readonly').grid(row=4, column=1)

# メインループの開始
root.mainloop()

weight_var = tk.DoubleVar(value=default_weight)
height_var = tk.DoubleVar(value=default_height)
bmi_var = tk.DoubleVar()
category_var = tk.StringVar()

tk.Label(root, text="体重 (kg)").grid(row=0, column=0)
tk.Spinbox(root, from_=30, to=150, increment=0.1, textvariable=weight_var, state="readonly").grid(row=0, column=1)

tk.Label(root, text="身長 (cm)").grid(row=1, column=0)
tk.Spinbox(root, from_=100, to=220, increment=0.1, textvariable=height_var, state="readonly").grid(row=1, colum

import tkinter as tk

def update_submit_button():
    if agree_var.get():
        submit_button.config(state=tk.NORMAL)
    else:
        submit_button.config(state=tk.DISABLED)

def clear_placeholder(event, placeholder):
    entry = event.widget

    if entry.get() == placeholder:
        entry.delete(0, tk.END)
        entry.config(fg='black')

def add_placeholder(event, placeholder):
    entry = event.widget

    if entry.get() == '':
        entry.insert(0, placeholder)
        entry.config(fg='grey')

root = tk.Tk()

# 名前の入力
tk.Label(root, text="名前").grid(row=0, column=0, padx=10, pady=5, sticky='e')
default_name = "山田 太郎"
name_entry = tk.Entry(root, fg='grey')
name_entry.insert(0, default_name)
name_entry.bind("<FocusIn>", lambda event: clear_placeholder(event, default_name))
name_entry.bind("<FocusOut>", lambda event: add_placeholder(event, default_name))
name_entry.grid(row=0, column=1, padx=10, pady=5)

# メールの入力
tk.Label(root, text="メールアドレス").grid(row=1, column=0, padx=10, pady=5, sticky='e')
default_email = "example@example.com"
email_entry = tk.Entry(root, fg='grey')
email_entry.insert(0, default_email)
email_entry.bind("<FocusIn>", lambda event: clear_placeholder(event, default_email))
email_entry.bind("<FocusOut>", lambda event: add_placeholder(event, default_email))
email_entry.grid(row=1, column=1, padx=10, pady=5)

# 電話番号の入力
tk.Label(root, text="電話番号").grid(row=2, column=0, padx=10, pady=5, sticky='e')
default_phone = "080-1234-5678"
phone_entry = tk.Entry(root, fg='grey')
phone_entry.insert(0, default_phone)
phone_entry.bind("<FocusIn>", lambda event: clear_placeholder(event, default_phone))
phone_entry.bind("<FocusOut>", lambda event: add_placeholder(event, default_phone))
phone_entry.grid(row=2, column=1, padx=10, pady=5)

# 住所の入力
tk.Label(root, text="住所").grid(row=3, column=0, padx=10, pady=5, sticky='e')
default_address = "東京都新宿区1-2-3"
address_entry = tk.Entry(root, fg='grey')
address_entry.insert(0, default_address)
address_entry.bind("<FocusIn>", lambda event: clear_placeholder(event, default_address))
address_entry.bind("<FocusOut>", lambda event: add_placeholder(event, default_address))
address_entry.grid(row=3, column=1, padx=10, pady=5)

# プライバシーポリシーへの同意
agree_var = tk.BooleanVar()
agree_check = tk.Checkbutton(root, text="プライバシーポリシーに同意する", variable=agree_var, command=update_submit_button)
agree_check.grid(row=4, columnspan=2, padx=10, pady=10)

# 送信ボタン
submit_button = tk.Button(root, text="送信", state=tk.DISABLED)
submit_button.grid(row=5, columnspan=2, padx=10, pady=20)

# メインループの開始
root.mainloop()

agree_var = tk.BooleanVar()
agree_check = tk.Checkbutton(root, text="プライバシーポリシーに同意する", variable=agree_var, command=update_submit_button)

def update_submit_button():
    if agree_var.get():
        submit_button.config(state=tk.NORMAL)
    else:
        submit_button.config(state=tk.DISABLED)