heyong.fu
119 lines
2.5 KiB
Python
119 lines
2.5 KiB
Python
# Python没有原生的switch-case语句，但可以通过以下几种方式来实现类似的功能：
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# if-elif-else结构：最直接的方法，适合简单的条件判断
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# 字典映射：推荐的方法，利用字典的键值对映射实现高效的条件分支
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# 函数字典：在字典中存储函数对象，实现复杂的逻辑处理
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# Python 3.10+ match语句：现代Python提供的模式匹配语法
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# 字典映射
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def switch_dict(case):
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switcher = {
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"A": "case A",
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"B": "case B",
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"C": "case C",
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}
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return switcher.get(case, "Defaule Case")
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result = switch_dict("A")
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print(result) # case A
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result = switch_dict("D")
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print(result) # Defaule Case
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# 使用函数字典
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def case_a():
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return "Action for case A"
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def case_b():
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return "Action for case B"
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def case_c():
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return "Action for case C"
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def case_default():
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return "Default action"
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def switch_funtion_dice(case):
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switer = {"A": case_a, "B": case_b, "C": case_c}
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fn = switer.get(case, case_default)
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return fn()
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result = switch_funtion_dice("A")
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print(result)
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result = switch_funtion_dice("F")
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print(result)
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# 自 Python 3.10 起，官方引入了结构化匹配（match 语句），可以原生实现类似 switch 的多分支选择功能。match 让代码更加优雅、可读性更强，尤其适用于分支较多、需要解构或复杂条件匹配的场景。
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def switch_match(case):
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"""
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使用 Python 3.10+ 的 match 语句实现 switch 功能
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这是最现代和强大的方法
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"""
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match case:
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case "A":
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return "Case A"
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case "B":
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return "Case B"
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case "C":
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return "Case C"
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case _:
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return "Default case"
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result = switch_match("A")
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print(result)
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result = switch_match("F")
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print(result) # Default case
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# 数值范围匹配
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def grade_evaluator(sorce):
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grade_map = {
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range(90, 101): "A",
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range(80, 90): "B",
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range(70, 80): "C",
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range(60, 70): "D",
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}
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for score_range, grade in grade_map.items():
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if sorce in score_range:
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return grade
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return "F"
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# 测试成绩评估
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scores = [
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{"scorce": 95},
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{"scorce": 85},
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{"scorce": 75},
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{"scorce": 65},
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{"scorce": 55},
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]
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for item in scores:
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grade = grade_evaluator(item["scorce"])
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item["grade"] = grade
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print(scores)
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def greet(name, msg="Hello"):
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print(f"{msg}, {name}!")
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greet("Alice") # 输出：Hello, Alice!
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greet("Bob", "Hi") # 输出：Hi, Bob!
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num_enough = 10
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print(num_enough is False) |