Pythonの書き方

name = "海"
print(name)

age = 20
if age >= 18:
    print("18歳以上です")
else:
    print("18歳未満です")

for number in range(1, 4):
    print(number)

def add(a, b):
    return a + b

print(add(2, 3))

fruits = ["りんご", "みかん"]
print(fruits[0])

name = "海"
print(f"こんにちは、{name}さん")

with open("notes.txt", encoding="utf-8") as file:
    print(file.read())

# 名前を表示する
print("海")

print(10 / 3)
print(10 // 3)
print(10 % 3)
print(2 ** 3)
total = 10
total += 2

age = 20
print(age == 20)
print(age >= 18 and age < 65)
print(not False)

name = None
if name is None:
    print("名前なし")

print(int("20") + 1)
print(float("1.5"))
print(str(20))
print(type(20))

name = input("名前：")
print(name)

name = "海"
print("こんにちは、" + name)
print(len(name))

print(" 海 ".strip())
print("海,空".split(","))
print("海です".replace("海", "空"))
print("、".join(["海", "空"]))

text = "hello"
print(text[0])
print(text[1:4])
print(text[-1])

print("海" in ["海", "空"])
age = 20
label = "成人" if age >= 18 else "未成年"

count = 0
while count < 3:
    print(count)
    count += 1

for n in [1, 2, 3, 4]:
    if n == 2:
        continue
    if n == 4:
        break
    print(n)

for i, name in enumerate(["海", "空"], start=1):
    print(i, name)
for name, age in zip(["海", "空"], [20, 21]):
    print(name, age)

def greet(name="ゲスト"):
    return "こんにちは、" + name

print(greet(name="海"))

def show(*names):
    for name in names:
        print(name)

show("海", "空")

double = lambda n: n * 2
print(double(3))

def later():
    pass

color = "red"
match color:
    case "red":
        print("赤")
    case _:
        print("その他")

items = ["りんご"]
items.append("みかん")
last = items.pop()

doubled = [n * 2 for n in [1, 2, 3]]
adults = [n for n in [15, 20, 30] if n >= 18]

user = {"name": "海"}
user["age"] = 20
print(user.get("nickname", "名無し"))

user = {"name": "海", "age": 20}
for key, value in user.items():
    print(key, value)

pair = ("海", 20)
name, age = pair

names = {"海", "空", "海"}
names.add("陸")
print(len(names))

nums = [3, 1, 2]
print(sorted(nums))
nums.sort()

nums = [1, 2, 3]
print(sum(nums))
print(min(nums))
print(max(nums))

try:
    number = int("海")
except ValueError:
    print("数字を入力してください")
finally:
    print("終了")

age = -1
if age < 0:
    raise ValueError("年齢は0以上です")

with open("notes.txt", "w", encoding="utf-8") as file:
    file.write("こんにちは")

import math
from datetime import date
print(math.sqrt(9))
print(date.today())

import json
text = json.dumps({"name": "海"}, ensure_ascii=False)
user = json.loads(text)

import csv
with open("data.csv", newline="", encoding="utf-8") as file:
    for row in csv.reader(file):
        print(row)

from pathlib import Path
path = Path("notes.txt")
print(path.exists())

class User:
    def __init__(self, name):
        self.name = name

    def greet(self):
        return "こんにちは、" + self.name

user = User("海")

def main():
    print("こんにちは")

if __name__ == "__main__":
    main()

def add(a: int, b: int) -> int:
    return a + b

def numbers():
    for n in range(3):
        yield n

for n in numbers():
    print(n)