程序员的 Python 基本提示和技巧?

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我们将涵盖一些有用的 python 技巧和提示，这些技巧和提示在为竞争性编程或为公司编写程序时非常有用，因为它们可以减少代码和优化执行。

使用模块 heapq 获取列表中的 n 个最大元素

示例

import heapq

marks = [91, 67, 34, 56, 78, 99, 87, 23, 78, 66]
print("Marks = ",marks)

print("Largest =",heapq.nlargest(2, marks))

输出

Marks =  [91, 67, 34, 56, 78, 99, 87, 23, 78, 66]
Largest = [99, 91]

使用模块 heapq 获取列表中 n 个最小元素

示例

import heapq

marks = [91, 67, 34, 56, 78, 99, 87, 23, 78, 66]
print("Marks = ",marks)

print("Smallest =",heapq.nsmallest(2, marks))

输出

Marks =  [91, 67, 34, 56, 78, 99, 87, 23, 78, 66]
Smallest = [23, 34]

从列表创建一个字符串

示例

myList = ['Hello', 'World']
print(" ".join(myList))

输出

Hello World

在一行中分配多个变量

示例

a, b, c = 10, 20, 30
print(a, b, c)

输出

10 20 30

在一行中循环列表中的元素：列表解析

示例

myList = [5, 12, 15, 18, 24, 32, 55, 65]

res = [number for number in myList if number % 5 == 0]

print("Displaying numbers divisible by 5 = ",res)

输出

Displaying numbers divisible by 5 = [5, 15, 55, 65]

两个数字的原地交换

示例

a, b = 50, 70
print("Before Swapping = ",a, b)

# swapping
a, b = b, a
print("After Swapping = ",a, b)

输出

Before Swapping = 50 70
After Swapping = 70 50

在一行中反转字符串

示例

# Reverse a string
myStr = "This is it!!!"

print("String = ",myStr)
print("Reversed String = ",myStr[::-1])

输出

String =  This is it!!!
Reversed String =  !!!ti si sihT

从两个相关序列创建字典

示例

# Creating a dictionary from two related sequences
s1 = ('Name', 'EmpId', 'Dept')
r1 = ('Jones', 767, 'Marketing')
print(dict (zip(s1, r1)))

输出

{'Name': 'Jones', 'EmpId': 767, 'Dept': 'Marketing'}

在 python 中检查对象

示例

# Inspect an object in Python

myList =[1, 3, 4, 7, 9]
print(dir(myList))

输出

['__add__', '__class__', '__contains__', '__delattr__', '__delitem__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__init_subclass__', '__iter__', '__le__', '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__reversed__', '__rmul__', '__setattr__', '__setitem__', '__sizeof__', '__str__', '__subclasshook__', 'append', 'clear', 'copy', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort']