处理字符串

Python for Developers 入门

Jasmin Ludolf

Senior Data Science Content Developer

字符串无处不在！

用字符串写成的 Hello

显示消息

处理文本输入

文件名

格式化输出

处理数据

¹ Image generated by ChatGPT

Python 识别单引号和双引号

# 可行
ingredient_name = 'San Marzano tomatoes'

# 也可行
ingredient_name = "San Marzano tomatoes"

' = 撇号 = 单引号

双引号的优势

# 单引号字符串中包含撇号
ingredient_name = 'Chef's special seasoning'
print(ingredient_name)

SyntaxError: invalid syntax.

# 双引号字符串中包含撇号
ingredient_name = "Chef's special seasoning"
print(ingredient_name)

Chef's special seasoning

句子与段落

recipe_step = "Heat olive oil in a large pan and sauté garlic until fragrant"

多行字符串

# 跨多行创建字符串变量
recipe_instructions = """1. Bring a large pot of salted water to boil and cook pasta
2. Heat olive oil in a pan and sauté minced garlic until fragrant
3. Add chopped tomatoes and simmer for 10 minutes
4. Toss cooked pasta with tomato sauce and fresh basil leaves
"""

"""text"""：多行字符串
- 提升可读性
- 用于文档
- 长文本，如说明或错误信息

方法

方法：仅适用于特定数据类型的函数
str 方法
- 标准化输入或转换文本

# 调用字符串方法
string_variable.method()

替换字符串片段

.replace(text_to_be_replaced, text_to_change_it_to)

welcome_message = "Welcome to the recipe scaler, George"

welcome_message = welcome_message.replace("George", "John")

print(welcome_message)

Welcome to the recipe scaler, John

更改大小写

标准化用户输入，如电子邮件

ingredient_name = "Basil Leaves"

# 转为小写
ingredient_name = ingredient_name.lower()
print(ingredient_name)

basil leaves

# 转为大写
ingredient_name = ingredient_name.upper()
print(ingredient_name)

BASIL LEAVES

开始练习吧！

Python for Developers 入门