11个Python的循环技巧分享

# 使用列表推导式创建多个空列表
num_lists = 5
empty_lists = [[] for _ in range(num_lists)]

print(empty_lists)

# 创建奇数和偶数列表
numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
odd_numbers = []
even_numbers = []

for num in numbers:
    if num % 2 == 0:
        even_numbers.append(num)
    else:
        odd_numbers.append(num)

print("奇数列表:", odd_numbers)
print("偶数列表:", even_numbers)

# 根据字符串长度创建多个列表
words = ["apple", "banana", "orange", "pear", "grape", "kiwi"]
short_words = []
medium_words = []
long_words = []

for word in words:
    if len(word) < 5:
        short_words.append(word)
    elif len(word) < 7:
        medium_words.append(word)
    else:
        long_words.append(word)

print("短单词列表:", short_words)
print("中等长度单词列表:", medium_words)
print("长单词列表:", long_words)

# 根据数据类型创建多个列表
data = [1, 2.5, "apple", 4, "banana", 6.7, "orange", 8, 9, "pear"]
integers = []
floats = []
strings = []

for item in data:
    if isinstance(item, int):
        integers.append(item)
    elif isinstance(item, float):
        floats.append(item)
    elif isinstance(item, str):
        strings.append(item)

print("整数列表:", integers)
print("浮点数列表:", floats)
print("字符串列表:", strings)

# 根据用户输入动态创建多个列表
num_lists = int(input("请输入要创建的列表数量: "))
lists = [[] for _ in range(num_lists)]

print("已创建", num_lists, "个空列表:", lists)

# 创建包含特定范围的数字的多个列表
num_lists = 10
range_lists = [[] for _ in range(num_lists)]

for num in range(10):
    range_lists[num % num_lists].append(num)

print("按照个位数存储的列表:")
for i, lst in enumerate(range_lists):
    print(f"列表{i}:", lst)

# 根据键的哈希值创建多个列表
data = {"apple": 3, "banana": 5, "orange": 2, "pear": 4, "grape": 6}
num_lists = 3
hash_lists = [[] for _ in range(num_lists)]

for key, value in data.items():
    hash_index = hash(key) % num_lists
    hash_lists[hash_index].append((key, value))

print("根据键的哈希值存储的列表:")
for i, lst in enumerate(hash_lists):
    print(f"列表{i}:", lst)

# 根据学生对象的成绩创建多个列表
class Student:
    def __init__(self, name, score):
        self.name = name
        self.score = score

students = [
    Student("Alice", 85),
    Student("Bob", 60),
    Student("Charlie", 75),
    Student("David", 40),
    Student("Emma", 95)
]

passing_students = []
failing_students = []

for student in students:
    if student.score >= 60:
        passing_students.append(student)
    else:
        failing_students.append(student)

print("及格学生列表:")
for student in passing_students:
    print(f"{student.name}: {student.score}")

print("\n不及格学生列表:")
for student in failing_students:
    print(f"{student.name}: {student.score}")

# 根据索引范围创建多个列表
numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
num_lists = 3
split_lists = []

for i in range(num_lists):
    start_index = i * len(numbers) // num_lists
    end_index = (i + 1) * len(numbers) // num_lists
    split_lists.append(numbers[start_index:end_index])

print("切分后的列表:")
for i, lst in enumerate(split_lists):
    print(f"列表{i + 1}:", lst)

# 根据列表元素的值进行分组创建多个列表
numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
odd_numbers = []
even_numbers = []

for num in numbers:
    if num % 2 == 0:
        even_numbers.append(num)
    else:
        odd_numbers.append(num)

print("奇数列表:", odd_numbers)
print("偶数列表:", even_numbers)

# 根据元素是否满足条件创建多个列表
numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
greater_than_5 = []
less_than_5 = []

for num in numbers:
    if num >= 5:
        greater_than_5.append(num)
    else:
        less_than_5.append(num)

print("大于等于5的数字列表:", greater_than_5)
print("小于5的数字列表:", less_than_5)