Hello，大家好，我是Alex~
Python现在非常流行，主要是因为它简单，容易学习。你可以用它来完成很多任务，比如数据科学和机器学习、 web开发、脚本编写、自动化等。
这里总结了20条很有用的tips给你：
01?把列表中的值作为参数传递给方法
可以使用" * "提取列表中的所有元素：
my_list= [1, 2, 3, 4]print(my_list)? # [1, 2, 3, 4]print(*my_list)? # 1 2 3 4
当我们想将列表中的所有元素作为方法参数传递时，这很有用：
def sum_of_elements(*arg):
? ? total = 0
? ? for i in arg:
? ? ? ? total += i
? ? return total
result = sum_of_elements(*[1, 2, 3, 4])
print(result)? # 10
02?获取列表的所有中间元素
_, *elements_in_the_middle, _ = [1, 2, 3, 4, 5, 6, 7, 8]
print(elements_in_the_middle) # [2, 3, 4, 5, 6, 7]
03?一行赋值多个变量
one, two, three, four = 1, 2, 3, 4
04?列表推导
你可以使用推导如，让我们将列表中的每个数字都取二次方:
numbers = [1, 2, 3, 4, 5]
squared_numbers = [num * num for num in numbers]
print(squared_numbers)
推导不仅仅局限于使用列表。还可以将它们与字典、集合和生成器一起使用。让我们看另一个例子，使用字典推导将一个字典的值提升到二阶：
Comprehensions are not just limited to working with lists. You can also use them with dictionaries, sets, and generators as well.
dictionary = {'a': 4, 'b': 5}squared_dictionary= {key: num * num for (key, num) in dictionary.items()}print(squared_dictionary)? # {'a': 16, 'b': 25}
05?一行打印多个元素
print("Hello", end="")
print("World")? # HelloWorld
print("Hello", end=" ")
print("World")? # Hello World
print('words',? 'with', 'commas', 'in', 'between', sep=', ')
# words, with, commas, in, between
06 不使用循环来重复字符串
name = "Banana"
print(name * 4)? # BananaBananaBananaBanana
07?打印多个值，每个值之间使用自定义分隔符
你可以很容易地做高级打印：
print("29", "01", "2022", sep="/")? # 29/01/2022
print("name", "domain.com", sep="@")? # name@domain.com
08 不能在变量名的开头使用数字
four_letters = “abcd” # this works4_letters = “abcd” # this doesn’t work
09 不能在变量名的开头使用操作符
+variable = “abcd”? # this doesn’t work
10?颠倒列表的顺序
my_list = ['a', 'b', 'c', 'd']
my_list.reverse()
print(my_list)? # ['d', 'c', 'b', 'a']
11 使用step函数对字符串切片
my_string= "This is just a sentence"print(my_string[0:5])? # This# Take three steps forwardprint(my_string[0:10:3])? # Tsse
12 反向切片
my_string = "This is just a sentence"
print(my_string[10:0:-1])? # suj si sih
# Take two steps forward
print(my_string[10:0:-2])? # sjs i
13 只有开始或结束索引的部分切片
表示切片的开始和结束的索引可以是可选的。
my_string = "This is just a sentence"
print(my_string[4:])? # is just a sentence
print(my_string[:3])? # Thi
14?你不能把0作为数字的第一个数字
number = 0110 # this doesn't work
15 Floor 除法
print(3/2)? # 1.5
print(3//2)? # 1
16 == 和 “is” 的差别
" is "检查两个变量是否指向内存中的同一个对象。" == "比较这两个对象的值是否相等。
first_list = [1, 2, 3]
second_list = [1, 2, 3]
# Is their actual value the same
print(first_list == second_list)? # True
# Are they pointing to the same object in memory
print(first_list is second_list)?
# False, since they have same values, but in different objects in memory
third_list = first_list
print(third_list is first_list)?
# True, since both point to the same object in memory
17 更改分配给另一个变量的变量的值
当一个变量被赋值给另一个变量时，它的值实际上被复制到第二个变量中。这意味着第一个变量之后的任何变化都不会反映在第二个变量中：
first = "An initial value"
second = first
first = "An updated value"
print(first)? # An updated value
print(second)? # An initial value
18 检查一个字符串是否大于另一个字符串
first = "abc"
second = "def"
print(first < second)? # True
second = "ab"
print(first < second)? # False
19 检查字符串是不是从特定字符开始的
my_string = "abcdef"
print(my_string.startswith("b"))? # False
20 使用id()找到变量的唯一id
print(id(1))? # 4325776624
print(id(2))? # 4325776656
print(id("string"))? # 4327978288