深入解析Python中占位符%的使用方法

name = "Alice"
age = 25
message = "Hello, %s! You are %d years old." % (name, age)
print(message)
# 输出：Hello, Alice! You are 25 years old.

pi = 3.141592653589793
formatted_pi = "The value of pi is %.2f" % pi
print(formatted_pi)
# 输出：The value of pi is 3.14

text = "Python"
formatted_text = "Language: %-10s is amazing!" % text
print(formatted_text)
# 输出：Language: Python     is amazing!

person = {'name': 'Bob', 'age': 30}
message = "Person: %(name)s, Age: %(age)d" % person
print(message)
# 输出：Person: Bob, Age: 30

from datetime import datetime

current_time = datetime.now()
formatted_time = "Current time: %Y-%m-%d %H:%M:%S" % current_time
print(formatted_time)
# 输出：Current time: 2023-01-01 12:30:45

user_input = "User input"
safe_message = "Input: %s" % user_input
print(safe_message)
# 输出：Input: User input

percentage = 25
escaped_percent = "The percentage is %d%%" % percentage
print(escaped_percent)
# 输出：The percentage is 25%

name = "Alice"
age = 25
message = "Hello, {}! You are {} years old.".format(name, age)
print(message)
# 输出：Hello, Alice! You are 25 years old.

name = "Alice"
age = 25
message = f"Hello, {name}! You are {age} years old."
print(message)
# 输出：Hello, Alice! You are 25 years old.

pi = 3.141592653589793
formatted_pi = "The value of pi is {:.2f}".format(pi)
print(formatted_pi)
# 输出：The value of pi is 3.14

price = 99
formatted_price = "The price is ${:0>5}".format(price)
print(formatted_price)
# 输出：The price is $00099