Catalog

️ Preface

Topic 1

analysis

answer

Topic two

analysis

answer

Topic three

analysis

answer

Topic four

analysis

answer

Topic 5

analysis

answer

️​​​​​​​ Last

️ Preface

The topic of this time is from Mr. dongfuguo Python Programming questions It mainly introduces to you Python Classic example < Use of built-in functions and operators >, Take you to master Python Basics , I hope you can gain more knowledge here ！ Let's learn together ！ Progress together ！

Topic 1

analysis

  This topic is less difficult , Mainly investigate the use of functions and lists .

answer

def main(lst):
for i in range(len(lst)):
lst[i] = lst[i].lower()
return lst

Topic two

analysis

The difficulty of this problem is medium , Mainly investigate the use of operators and built-in functions , It's easy to think about which built-in function to use .

answer

def main(lst):
return sorted(lst,key=len,reverse=Ture)

About built-in functions sorted() Just look at the following code , The notes are very detailed

l1 = ['3www','4wwww','2ww','5wwwww']
# No, reverse=True By default, they are sorted from small to large
l2 = sorted(l1,key=len)
print(l2)
# Yes reverse=True It is sorted from big to small
l3 = sorted(l1,key= len,reverse=True)
print(l3)
# First of all, no reverse=True, List l4 Each value in i Conduct abs(i),
# Then sort the changed values in descending order 22<77<333
l4 = [22,-333,77]
l5 = sorted(l4,key=abs)
# Yes reverse=True List l4 Each value in i Conduct abs(i),
# Then sort the changed values in descending order 333>77>22
print(l5)
l6 = sorted(l4,key= abs,reverse=True)
print(l6)
Output results ：
['2ww', '3www', '4wwww', '5wwwww']
['5wwwww', '4wwww', '3www', '2ww']
[22, 77, -333]
[-333, 77, 22]

Topic three

analysis

This topic is relatively simple. It mainly focuses on the use of operators and built-in functions

answer

from operator import mul
def main(vector1,vector2):
res = 0
for i in range(len(vector1)):
s = mul(vector1[i],vector2[i])
res += s
return res

Topic four

​​​​​​​ 

analysis

This question is less difficult , Mainly investigate the use of operators and built-in functions  

answer

def main(lst):
return sorted(lst,key=len)[len(lst)-1]

Start with the list  sorted(lst,key=len) The operation of , It becomes a new list sorted by element string from small to large , So the longest string in the list is at the end of the new list , After that, I was using it ( New list [len(lst)-1]) Get the last element , You get the longest string .

Topic 5

analysis

  This question mainly examines the operator , Use of anonymous and built-in functions

answer

def main(lst):
return list(filter(lambda n:n!=0,lst)

Pass in the values of the original list one by one lambda n:n!=0 Anonymous function , If True Return to the new list .

️​​​​​​​ Last

Thank you for seeing here ： In an unpublished article, Lu Xun said ：“ If you understand the code, you must operate it yourself, so that you can better understand and absorb .”
One last sentence ： A man can succeed in anything he has unlimited enthusiasm , Let's make progress together