Python高效地进行字符串操作的技巧分享

str1 = "Hello"
str2 = "World"
result = str1 + " " + str2
print(result)  # 输出: Hello World

words = ["Hello", "World", "!"]
result = " ".join(words)
print(result)  # 输出: Hello World !

name = "Alice"
age = 30
result = "My name is %s and I am %d years old." % (name, age)
print(result)  # 输出: My name is Alice and I am 30 years old.

result = "My name is {} and I am {} years old.".format(name, age)
print(result)  # 输出: My name is Alice and I am 30 years old.

result = f"My name is {name} and I am {age} years old."
print(result)  # 输出: My name is Alice and I am 30 years old.

s = "Python is awesome"
print(s.find("is"))  # 输出: 7
print(s.index("awesome"))  # 输出: 10

s = "I love Python"
new_s = s.replace("love", "like")
print(new_s)  # 输出: I like Python

s = "apple,banana,cherry"
fruits = s.split(",")
print(fruits)  # 输出: ['apple', 'banana', 'cherry']

s = "  Hello World  "
print(s.strip())  # 输出: Hello World

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

s = "Python is Fun"
print(s.upper())  # 输出: PYTHON IS FUN
print(s.lower())  # 输出: python is fun
print(s.capitalize())  # 输出: Python is fun
print(s.title())  # 输出: Python Is Fun

import re
s = "The price is $100"
match = re.search(r"\$\d+", s)
if match:
    print(match.group())  # 输出: $100

s = "2024-10-15"
new_s = re.sub(r"-", "/", s)
print(new_s)  # 输出: 2024/10/15

s = "你好"
s_bytes = s.encode('utf-8')
print(s_bytes)  # 输出: b'\xe4\xbd\xa0\xe5\xa5\xbd'
s_decoded = s_bytes.decode('utf-8')
print(s_decoded)  # 输出: 你好

s = "12345"
print(s.isdigit())  # 输出: True

s = "Hello"
print(s.isalpha())  # 输出: True

s = "Hello123"
print(s.isalnum())  # 输出: True

str_list = []
for i in range(1000):
    str_list.append("word")
result = "".join(str_list)

import io
s_io = io.StringIO()
for i in range(1000):
    s_io.write("word")
result = s_io.getvalue()