刚入门Python,写代码总在"重复造轮子"?这几个进阶基础知识点,不用啃复杂文档,练熟直接少走弯路,代码简洁又高效~
1. 集合(set):去重+判断的"极速工具"
还在靠列表遍历去重?集合自带去重属性,效率翻倍:
python
# 列表去重(繁琐且慢)
nums = [1, 2, 2, 3, 3, 3]
unique_nums = []
for num in nums:
if num not in unique_nums:
unique_nums.append(num)
print(unique_nums) # 输出: [1,2,3]
# 集合去重(一行搞定)
unique_nums = list(set(nums))
print(unique_nums) # 输出: [1,2,3](顺序不保证,需排序可加sorted())
判断元素是否存在,集合比列表快100倍(大数据量更明显):
fruit_set = {"apple", "banana", "cherry"}
print("apple" in fruit_set) # 输出: True(O(1)时间复杂度)
2. enumerate:循环时"顺便"拿索引
遍历列表想同时要索引和元素?别用 range(len()) 了:
python
fruits = ["apple", "banana", "cherry"]
# 传统写法(麻烦且不优雅)
for i in range(len(fruits)):
print(f"索引{i}:{fruits[i]}")
# enumerate写法(直接获取索引+元素)
for idx, fruit in enumerate(fruits, start=1): # start指定索引起始值
print(f"第{idx}个水果:{fruit}") # 输出: 第1个水果:apple...
3. zip:多列表"配对"的神器
想同时遍历多个列表?zip直接打包,不用手动索引对齐:
python
names = ["张三", "李四", "王五"]
scores = [85, 92, 78]
subjects = ["数学", "语文", "英语"]
# 传统写法(容易出错)
for i in range(len(names)):
print(f"{names[i]} {subjects[i]}:{scores[i]}分")
# zip打包(简洁且安全)
for name, subject, score in zip(names, subjects, scores):
print(f"{name} {subject}:{score}分") # 输出: 张三 数学:85分...
打包后转字典更方便:
python
student_scores = dict(zip(names, scores))
print(student_scores) # 输出: {'张三':85, '李四':92, '王五':78}
这三个技巧都是日常开发高频用到的,看似简单却能解决很多冗余场景~ 赶紧复制代码实测,练熟直接提升代码整洁度!