一看就会的20个“非常有用”的python小技巧，你一定要试试

my_list = [1, 2, 3, 4]

print(my_list)  # [1, 2, 3, 4]

print(*my_list)  # 1 2 3 4

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

_, *elements_in_the_middle, _ = [1, 2, 3, 4, 5, 6, 7, 8]
print(elements_in_the_middle) # [2, 3, 4, 5, 6, 7]

one, two, three, four = 1, 2, 3, 4

numbers = [1, 2, 3, 4, 5]
squared_numbers = [num * num for num in numbers]

print(squared_numbers)

![](100 Helpful Python Tips You Can Learn Before Finishing Your Morning Coffee.assets/1_4D3OCbHOCfHiI8A3ru4xRQ.png)
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}

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

name = "Banana"
print(name * 4)  # BananaBananaBananaBanana

print("29", "01", "2022", sep="/")  # 29/01/2022

print("name", "domain.com", sep="@")  # name@domain.com

four_letters = “abcd” # this works4_letters = “abcd” # this doesn’t work

+variable = “abcd”  # this doesn’t work

my_list = ['a', 'b', 'c', 'd']

my_list.reverse()

print(my_list)  # ['d', 'c', 'b', 'a']

my_string = "This is just a sentence"
print(my_string[0:5])  # This

# Take three steps forward
print(my_string[0:10:3])  # Tsse

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

my_string = "This is just a sentence"
print(my_string[4:])  # is just a sentence

print(my_string[:3])  # Thi

number = 0110 # this doesn't work

print(3/2)  # 1.5
print(3//2)  # 1

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

first = "An initial value"
second = first
first = "An updated value"

print(first)  # An updated value
print(second)  # An initial value

first = "abc"
second = "def"
print(first < second)  # True
second = "ab"
print(first < second)  # False

my_string = "abcdef"
print(my_string.startswith("b"))  # False

print(id(1))  # 4325776624
print(id(2))  # 4325776656
print(id("string"))  # 4327978288