【Python知识宝库】一文向您详细介绍 [:-1]和[::-1]

string[start:stop:step]

s = "Hello, World!"
print(s[0:5])  # 输出 "Hello"
print(s[7:12])  # 输出 "World"
print(s[0:13:2])  # 输出 "Hlo ol!"

s = "Hello, World!"
print(s[:-1])  # 输出 "Hello, World"

# 去除字符串末尾的换行符
s = "Hello, World!\n"
print(s[:-1])  # 输出 "Hello, World!"
# 去除字符串末尾的标点符号
s = "Hello, World!"
print(s[:-1])  # 输出 "Hello, World"
# 生成不包含最后一个字符的新字符串
s = "Python"
print(s[:-1])  # 输出 "Pytho"

s = "Hello, World!"
print(s[::-1])  # 输出 "!dlroW ,olleH"

# 反转字符串
s = "Hello, World!"
print(s[::-1])  # 输出 "!dlroW ,olleH"
# 检查回文字符串
def is_palindrome(s):
    return s == s[::-1]
print(is_palindrome("racecar"))  # 输出 True
print(is_palindrome("hello"))  # 输出 False
# 反转字符串并生成新字符串
s = "Python"
reversed_s = s[::-1]
print(reversed_s)  # 输出 "nohtyP"

def remove_trailing_punctuation(s):
    # 去除字符串末尾的标点符号
    while s and not s[-1].isalnum():
        s = s[:-1]
    return s
def is_palindrome(s):
    # 检查字符串是否是回文字符串
    return s == s[::-1]
def process_string(s):
    # 去除末尾标点符号并检查是否是回文字符串
    s = remove_trailing_punctuation(s)
    return s, is_palindrome(s)
# 测试
s = "A man, a plan, a canal, Panama!"
processed_s, is_palindrome_result = process_string(s)
print(f"处理后的字符串: {processed_s}")
print(f"是否是回文字符串: {is_palindrome_result}")

处理后的字符串: A man, a plan, a canal, Panama
是否是回文字符串: True