ython字符串处理实用技巧分享

sentence = "Python is awesome"
words = sentence.split()  # 默认按空格分割
print(words)  # 输出: ['Python', 'is', 'awesome']

# 按照逗号分割字符串
csv = "apple,banana,orange"
items = csv.split(',')
print(items)  # 输出: ['apple', 'banana', 'orange']

words = ['Python', 'is', 'awesome']
sentence = ' '.join(words)  # 使用空格连接
print(sentence)  # 输出: Python is awesome

items = ['apple', 'banana', 'orange']
csv = ','.join(items)  # 使用逗号连接
print(csv)  # 输出: apple,banana,orange

s = "   hello world   "
cleaned = s.strip()
print(cleaned)  # 输出: hello world

# 列表推导式，将字符串列表中的元素转换为大写
words = ['hello', 'world', 'python']
upper_words = [word.upper() for word in words]
print(upper_words)  # 输出: ['HELLO', 'WORLD', 'PYTHON']

# 生成器表达式，只保留长度大于 5 的字符串
long_words = (word for word in words if len(word) > 5)
print(list(long_words))  # 输出: ['python']

filename = "example.txt"
print(filename.startswith("ex"))  # 输出: True
print(filename.endswith(".txt"))  # 输出: True

s = "Hello, World!"
new_s = s.replace("World", "Python")
print(new_s)  # 输出: Hello, Python!

s = "Hello, World!"
print(s.find("World"))  # 输出: 7
print(s.find("Python"))  # 输出: -1

print(s.index("World"))  # 输出: 7
# print(s.index("Python"))  # 会抛出 ValueError 异常

s = "hello hello world"
print(s.count("hello"))  # 输出: 2

s = "Hello, World!"
substring = s[7:12]
print(substring)  # 输出: World

import re

s = "hello 123 world 456"
numbers = re.findall(r'\d+', s)
print(numbers)  # 输出: ['123', '456']

new_s = re.sub(r'\d+', '###', s)
print(new_s)  # 输出: hello ### world ###

filename = "example.txt"
print(filename.startswith("ex"))  # 输出: True
print(filename.endswith(".txt"))  # 输出: True

s1 = "hello"
s2 = "123"
s3 = "hello123"
s4 = "hello 123"

print(s1.isalpha())  # 输出: True
print(s2.isdigit())  # 输出: True
print(s3.isalnum())  # 输出: True
print(s4.isalnum())  # 输出: False

s = "Hello, World!"
print(s.lower())  # 输出: hello, world!
print(s.upper())  # 输出: HELLO, WORLD!

s = "hello world"
print(s.capitalize())  # 输出: Hello world
print(s.title())  # 输出: Hello World

s = "hello"
print(s.center(10, '*'))  # 输出: **hello***
print(s.ljust(10, '-'))  # 输出: hello-----
print(s.rjust(10, '='))  # 输出: =====hello

text = "Hello\nWorld\nPython"
lines = text.splitlines()
print(lines)  # 输出: ['Hello', 'World', 'Python']

s = "hello world python"
parts = s.partition(" ")
print(parts)  # 输出: ('hello', ' ', 'world python')

parts = s.rpartition(" ")
print(parts)  # 输出: ('hello world', ' ', 'python')

number = "42"
padded_number = number.zfill(5)
print(padded_number)  # 输出: 00042

s = "Hello, World!"
print(s.swapcase())  # 输出: hELLO, wORLD!

translation_table = str.maketrans("aeiou", "12345")
s = "hello world"
new_s = s.translate(translation_table)
print(new_s)  # 输出: h2ll4 w4rld