Python实现排序

  在Python中可以使用提供的sort排序法对list实现排序。
  Python提供两种内置排序的函数分别是sort()和sorted()，这两种函数用法差别在于sort()会直接修改原始的list进行排序，sorted()可迭代对象排序并返回新的list。

  sort()函数参数：

list.sort(key=None, reverse=False)
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• 实现整数的排序

# 使用sort升序
list = [4, 5, 8, 3, 7, 1, 2, 6, 10, 9]
print("before:", list)
list.sort()
print("result:", list)
print("after:", list)
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before: [4, 5, 8, 3, 7, 1, 2, 6, 10, 9]
result: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
after: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

# 使用sort降序
list = [4, 5, 8, 3, 7, 1, 2, 6, 10, 9]
print("before:", list)
list.sort(reverse=True)
print("result:", list)
print("after:", list)
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before: [4, 5, 8, 3, 7, 1, 2, 6, 10, 9]
result: [10, 9, 8, 7, 6, 5, 4, 3, 2, 1]
after: [10, 9, 8, 7, 6, 5, 4, 3, 2, 1]

# 使用sorted升序
list = [4, 5, 8, 3, 7, 1, 2, 6, 10, 9]
print("before:", list)
print("result:", sorted(list))
print("after:", list)
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before: [4, 5, 8, 3, 7, 1, 2, 6, 10, 9]
result: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
after: [4, 5, 8, 3, 7, 1, 2, 6, 10, 9]

# 使用sorted降序
list = [4, 5, 8, 3, 7, 1, 2, 6, 10, 9]
print("before:", list)
print("result:", sorted(list, reverse=True))
print("after:", list)
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before: [4, 5, 8, 3, 7, 1, 2, 6, 10, 9]
result: [10, 9, 8, 7, 6, 5, 4, 3, 2, 1]
after: [4, 5, 8, 3, 7, 1, 2, 6, 10, 9]

• 实现浮点数的排序

# 使用sort升序
list = [12.8, 25.6, 51.8, 72.7, 99.8, 38.7, 45.9, 66.8, 81.2, 1.7]
print("before:", list)
list.sort(key=float)
print("result:", list)
print("after:", list)
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before: [12.8, 25.6, 51.8, 72.7, 99.8, 38.7, 45.9, 66.8, 81.2, 1.7]
result: [1.7, 12.8, 25.6, 38.7, 45.9, 51.8, 66.8, 72.7, 81.2, 99.8]
after: [1.7, 12.8, 25.6, 38.7, 45.9, 51.8, 66.8, 72.7, 81.2, 99.8]

# 使用sort降序
list = [12.8, 25.6, 51.8, 72.7, 99.8, 38.7, 45.9, 66.8, 81.2, 1.7]
print("before:", list)
list.sort(key=float, reverse=True)
print("result:", list)
print("after:", list)
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before: [12.8, 25.6, 51.8, 72.7, 99.8, 38.7, 45.9, 66.8, 81.2, 1.7]
result: [99.8, 81.2, 72.7, 66.8, 51.8, 45.9, 38.7, 25.6, 12.8, 1.7]
after: [99.8, 81.2, 72.7, 66.8, 51.8, 45.9, 38.7, 25.6, 12.8, 1.7]

# 使用sorted升序
list = [12.8, 25.6, 51.8, 72.7, 99.8, 38.7, 45.9, 66.8, 81.2, 1.7]
print("before:", list)
print("result:", sorted(list, key=float))
print("after:", list)
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before: [12.8, 25.6, 51.8, 72.7, 99.8, 38.7, 45.9, 66.8, 81.2, 1.7]
result: [1.7, 12.8, 25.6, 38.7, 45.9, 51.8, 66.8, 72.7, 81.2, 99.8]
after: [12.8, 25.6, 51.8, 72.7, 99.8, 38.7, 45.9, 66.8, 81.2, 1.7]

# 使用sorted降序
list = [12.8, 25.6, 51.8, 72.7, 99.8, 38.7, 45.9, 66.8, 81.2, 1.7]
print("before:", list)
print("result:", sorted(list, key=float, reverse=False))
print("after:", list)
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before: [12.8, 25.6, 51.8, 72.7, 99.8, 38.7, 45.9, 66.8, 81.2, 1.7]
result: [99.8, 81.2, 72.7, 66.8, 51.8, 45.9, 38.7, 25.6, 12.8, 1.7]
after: [12.8, 25.6, 51.8, 72.7, 99.8, 38.7, 45.9, 66.8, 81.2, 1.7]