lis = [‘a’, ‘b’, ‘c’, ‘d’, ‘e’, ‘f’]
new_lis = [element.upper().replace(‘_’, ‘’) for element in lis if element in lis]
print(new_lis)
keys = [‘a’, ‘b’, ‘c’, ‘d’, ‘e’]
dic = {key: None for key in keys if key in keys}
print(dic)
items = [(‘name’, ‘egon’), (‘age’, 19), (‘gender’, ‘male’)]
new_dic = {k:v for k,v in items if k != ‘gender’}
print(new_dic)
keys = [‘a’, ‘b’, ‘c’, ‘d’, ‘e’]
set_ = {key for key in keys if key in keys}
print(set_)
g = (i for i in range(10) if i > 3) # 此刻在g的内部一个值也没有
print(g)
print(next(g))
with open(r’D:Generative_formula.md’, mode=‘rt’,encoding=‘utf-8’) as f:
# 方案一：
# count = 0
# for line in f:
# # print(len(line))
# count += len(line)
# print(count)
# 方案二：效率最高
res = sum(len(line) for line in f)
print(res)
