[Python] and演算子の使い方

# 2つの条件が両方とも真である場合にのみ、全体が真となる
x = 10
y = 20
# xが5より大きく、かつyが15より大きい場合
if x > 5 and y > 15:
    print("Both conditions are true")
else:
    print("At least one condition is false")

Both conditions are true

# 短絡評価の例
def is_greater_than_five(num):
    print(f"Evaluating: {num} > 5")
    return num > 5
a = 3
b = 10
# aが5より大きく、かつbが5より大きい場合
if is_greater_than_five(a) and is_greater_than_five(b):
    print("Both numbers are greater than five")
else:
    print("At least one number is not greater than five")

Evaluating: 3 > 5
At least one number is not greater than five

# ユーザーの年齢と居住地をチェック
age = 25
location = "Tokyo"
# 年齢が20歳以上で、居住地がTokyoの場合
if age >= 20 and location == "Tokyo":
    print("You are eligible for the Tokyo event.")
else:
    print("You are not eligible for the Tokyo event.")

You are eligible for the Tokyo event.

# 数値のリストをチェック
numbers = [5, 12, 7, 18, 3]
# 各数値が10以上かつ20以下であるかを確認
for num in numbers:
    if num >= 10 and num <= 20:
        print(f"{num} is between 10 and 20")
    else:
        print(f"{num} is not between 10 and 20")

5 is not between 10 and 20
12 is between 10 and 20
7 is not between 10 and 20
18 is between 10 and 20
3 is not between 10 and 20

# ユーザーの入力をチェック
username = "admin"
password = "secure123"
# ユーザー名がadminで、パスワードがsecure123の場合
if username == "admin" and password == "secure123":
    print("Access granted")
else:
    print("Access denied")

Access granted

# データのリストをフィルタリング
data = [
    {"name": "Alice", "age": 30, "city": "New York"},
    {"name": "Bob", "age": 25, "city": "Tokyo"},
    {"name": "Charlie", "age": 35, "city": "Tokyo"}
]
# 年齢が30以上で、居住地がTokyoのデータを抽出
filtered_data = [person for person in data if person["age"] >= 30 and person["city"] == "Tokyo"]
print(filtered_data)

[{'name': 'Charlie', 'age': 35, 'city': 'Tokyo'}]

# 短絡評価の例
def check_condition():
    print("This function is called")
    return True
# 左側の条件が偽の場合、右側の関数は呼び出されない
result = False and check_condition()
print(result)

False

# 優先順位の例
a = True
b = False
c = True
# 括弧を使用して明示的に評価順序を指定
result = a and (b or c)
print(result)

True

# Noneの扱いの例
value = None
# valueがNoneでないかつ10より大きい場合
if value is not None and value > 10:
    print("Value is greater than 10")
else:
    print("Value is None or not greater than 10")

Value is None or not greater than 10

# Falseの扱いの例
condition1 = False
condition2 = True
# どちらかの条件がFalseの場合
if condition1 and condition2:
    print("Both conditions are true")
else:
    print("At least one condition is false")

At least one condition is false

# ユーザーの情報をチェック
age = 30
occupation = "Engineer"
location = "Tokyo"
# 年齢が25歳以上、職業がEngineer、居住地がTokyoの場合
if age >= 25 and occupation == "Engineer" and location == "Tokyo":
    print("Eligible for the engineering conference in Tokyo.")
else:
    print("Not eligible for the conference.")

Eligible for the engineering conference in Tokyo.

# SQLクエリの例
query = """
SELECT * FROM employees
WHERE age > 30 AND department = 'Sales' AND city = 'New York';
"""
print(query)

SELECT * FROM employees
WHERE age > 30 AND department = 'Sales' AND city = 'New York';

# Webアプリケーションでの条件処理
user_logged_in = True
has_permission = True
is_admin = False
# ユーザーがログインしていて、権限があり、管理者でない場合
if user_logged_in and has_permission and not is_admin:
    print("Access to user dashboard granted.")
else:
    print("Access denied.")

Access to user dashboard granted.

# 機械学習モデルの条件設定
import numpy as np
# データセットの条件
data_size = 1000
feature_count = 20
# モデルの条件
if data_size > 500 and feature_count >= 20:
    print("Proceed with model training.")
else:
    print("Insufficient data or features for training.")

Proceed with model training.