創(chuàng)建一個數(shù)組
books = ["python", "java", "scala", "c++"]
數(shù)組的打印
print(books)
數(shù)組元素的訪問,訪問第一個元素
message = books[0]
print(message)
訪問最后一個元素
message = books[len(books) - 1]
print(message)
快速訪問最后一個元素
message = books[-1]
print(message)
快速訪問倒數(shù)第二個元素
message = books[-2]
print(message)
修改數(shù)組中元素的值-根據(jù)index修改
message = "spark"
books[3] = message
print(books)
在數(shù)組中添加元素
方式1，在數(shù)組末尾添加元素
books.append("c++")
print(books)
在數(shù)組指定位置前插入新元素
例如在數(shù)組頭添加元素援雇，第一個參數(shù)為要插入位置的索引矛渴，第二個參數(shù)是值
books.insert(0, "hive")
print(books)
刪除元素-del語句
刪除最后一個元素
del books[-1]
print(books)
刪除元素-pop()語句，與del不同之處在于pop()方法會返回刪除元素
默認(rèn)情況下刪除數(shù)組最后一個元素
message = books.pop()
print(message)
根據(jù)需要刪除元素
例如刪除第一個元素
message = books.pop(0)
print(message)
根據(jù)值刪除元素--ps:remove()方法只會刪除第一次出現(xiàn)的元素
books.remove("scala")
print(books)
排序
books = ["python", "java", "scala", "c++"]
books_copy = books
按照字母的先后順序升序排列--ps:sort()方法永久性的排序惫搏，無法恢復(fù)到之前的數(shù)組
books_copy.sort()
print("books:", books) # books: ['c++', 'java', 'python', 'scala']
print("books_copy:", books_copy) # books_copy: ['c++', 'java', 'python', 'scala']
傳遞參數(shù)具温，逆序排列--ps:此方法也是不可逆的，無法得到之前的數(shù)組
books = ["python", "java", "scala", "c++"]
books.sort(reverse=True)
print(books)
臨時排序
books = ["python", "java", "scala", "c++"]
books_sorted = sorted(books)
print("books:", books) # books: ['python', 'java', 'scala', 'c++']
print("books_sorted:", books_sorted) # books_sorted: ['c++', 'java', 'python', 'scala']
sorted 逆序臨時排序
books_sorted = sorted(books, reverse=True)
print(books_sorted)
數(shù)組的反轉(zhuǎn)
books.reverse()
print(books)
books.reverse()
print(books) # 調(diào)用兩次reverse()方法回到原來的數(shù)組
數(shù)組的長度
length = len(books)
print(length)
循環(huán)
for 循環(huán)
books = ["python", "java", "scala", "c++"]
for book in books:
print(book)
for book in books:
print(book.title(), "is very important for me", "!")
創(chuàng)建數(shù)字列表--math
range()函數(shù)-ps:含頭不含尾
for value in range(1, 5):
print(value)
list()和range()合用構(gòu)造數(shù)組
numbers = list(range(1, 6))
print(numbers)
range()指定步長-ps:第一個參數(shù)是開始晶府，第二個參數(shù)是結(jié)尾桂躏，第三個參數(shù)是步長
numbers = list(range(1, 10, 2))
print(numbers)
range()函數(shù)構(gòu)造平方
numbers = []
for value in range(1, 11):
numbers.append(value**2)
print(numbers)
最大最小函數(shù)
min_value = min(numbers)
max_value = max(numbers)
print(min_value)
print(max_value)
求和函數(shù)
sum_value = sum(numbers)
print(sum_value)
創(chuàng)建數(shù)組-ps:注意沒有冒號
numbers = [value**2 for value in range(1, 11)]
print(numbers)
列表分片-切分
創(chuàng)建一個數(shù)組
numbers = [value**3 for value in range(1, 11)]
print(numbers) # [1, 8, 27, 64, 125, 216, 343, 512, 729, 1000]
獲取numbers的前三個數(shù)字并保存為新的數(shù)組
numbers03 = numbers[0: 3]
print("numbers03", numbers03) # numbers03 [1, 8, 27]
獲取2-5位置
numbers25 = numbers[2: 6]
print(numbers25) # [27, 64, 125, 216]
獲取前4個數(shù)字-ps:第一個參數(shù)可以不寫
numbers4 = numbers[: 4]
print(numbers4)
獲取索引2以及以后的數(shù)字
numbers2 = numbers[2:]
print(numbers2) # [27, 64, 125, 216, 343, 512, 729, 1000]
獲取倒數(shù)三位的數(shù)字
print(numbers[-3:])
遍歷切片
for value in numbers[-3:]:
print(value)
數(shù)組的復(fù)制
numbers_copy = numbers[:]
print(numbers_copy)
numbers.append(0)
print(numbers)
元組
dimensions = (200, 100, 300)
for value in dimensions:
print(value)
print("---------------")
元組數(shù)據(jù)的訪問
print(dimensions[0])
元組中的數(shù)據(jù)不容修改 eg: dimensions[0] = 23
但是可以重新定義元組
dimensions = (23, 234)
print(dimensions)
