Python Learning Note 002_ array _ tuples

Creating a normal array

>>> member=["Shandong Gold", "nine Yang Shares"]

>>> Member

[' Shandong Gold ', ' nine Yang shares ']

Create a mixed array (the array holds various types of data)

>>> mix=[1,2.3, "520", ["Haha"]]

>>> Mix

[1, 2.3, ' 520 ', [' Haha ']

Create an empty array

>>> empty=[]

>>> Empty

[]

Adding elements to an array

Append (), appends an element to the end of the array

Extend (), extending another list with one list, and appending the element to the end

Insert (), inserts an element into the specified position of the array

>>> Member.append ("Shenzhen airport")

>>> Len (member)

3

>>>

>>> Member.extend (["Merchant Steamer", "Ping An Bank"])

>>> Member

[' Shandong Gold ', ' nine-Yang shares ', ' Shenzhen airport ', ' merchant steamer ', ' Ping An bank '

>>> Len (member)

5

>>> Member.insert (2, "Tuo card Willing")

>>> Member

[' Shandong Gold ', ' nine Yang shares ', ' Tuo licensing ', ' Shenzhen airport ', ' merchant steamer ', ' Ping An bank '

>>>

Get an element in an array

>>> Member[1]

' Nine-Yang shares '

>>>

>>> member[1] = "Nine Yang shares-nine Yang Martial"

>>> Member

[' Shandong Gold ', ' nine Yang shares-nine Yang Martial, ' Tuo licensing ', ' Shenzhen airport ', ' merchant steamer ', ' Ping An bank '

>>>

To delete an element in an array

Remove () to delete the specified name element, if the specified value does not exist, an error will be

Del, which is a statement, not a method, can delete an entire array, or you can delete an element at a specified position

Pop (), removes the last element from the array and returns the value, or removes the element that specifies the subscript

>>> member.remove ("Shandong Gold")

>>> Member

[' Nine Yang shares-nine Yang Martial, ' Tuo licensing ', ' Shenzhen airport ', ' merchant steamer ', ' Ping An Bank ']

>>> del Member[1]

>>> Member

[' Nine Yang shares-nine Yang Martial, ' ' Shenzhen airport ', ' merchant steamer ', ' Ping An Bank ']

>>>

>>>

>>> last = Member.pop ()

>>> Member

[' Nine Yang shares-nine Yang Martial, ' Shenzhen airport ', ' Merchants Steamship ']

>>> Last

' Ping An Bank '

>>> Item=member.pop (1)

>>> Member

[' Nine Yang shares-nine Yang Martial, ' ' China Merchants Steamship ']

>>> Item

' Shenzhen airport '

>>>

Array shards: You can get multiple elements at once

>>> Member[0:1] # This is a copy of the content, the original array is unchanged

[' Nine Yang shares-nine Yang Martial magic ']

>>> Member

[' Nine Yang shares-nine Yang Martial, ' ' China Merchants Steamship ']

>>>

>>> Member[:1] #下标为1之前的都获取到

[' Nine Yang shares-nine Yang Martial magic ']

>>> member[1:] #从下标为1开始获取

[' Merchant steamer ']

>>> member[:] #获取整个数组

[' Nine Yang shares-nine Yang Martial, ' ' China Merchants Steamship ']

>>>

element is not in an array, you can use in or not

>>>

>>> "Awei" not in member

True

>>> "merchant Steamer" in member

True

>>>

#指定元素出现的次数

>>> member.count ("haha")

0

>>> Member.count ("Merchant Steamer")

1

# Specify the position of the element in the array

>>> Member.index ("Merchant Steamer")

1

>>>

Flipping an array

>>> Member.reverse ()

>>> Member

[' China Merchants Steamship ', ' nine Yang shares-nine Yang Martial magic ']

>>>

Sort sorted, it's a sort of merge

>>> Member.sort ()

>>> Member

[' Nine Yang shares-nine Yang Martial, ' ' China Merchants Steamship ']

>>>

>>> Member.sort (reverse=true)

>>> Member

[' China Merchants Steamship ', ' nine Yang shares-nine Yang Martial magic ']

>>>

Re-emphasize that

>>> member1=member[:] #是一种数组的拷贝

>>> Member1

[' China Merchants Steamship ', ' nine Yang shares-nine Yang Martial magic ']

>>> Member2=member #不是拷贝, referencing the same arrays

>>> Member2

[' China Merchants Steamship ', ' nine Yang shares-nine Yang Martial magic ']

>>> Member.sort ()

>>> Member1

[' China Merchants Steamship ', ' nine Yang shares-nine Yang Martial magic ']

>>> Member2

[' Nine Yang shares-nine Yang Martial, ' ' China Merchants Steamship ']

>>>

Tuple tuples and arrays are very similar, but tuples cannot be modified.

For tuples, commas are key, and parentheses do not necessarily have to be

>>> items= ("Nine Yang", "Big ship", "Peace", "gold")

>>> Items

(' Nine Yang ', ' Big ship ', ' peace ', ' gold ')

>>> Items[2]

Peace

>>> Items[:1]

(' Nine Yang ',)

>>> items[2:]

(' Peace ', ' gold ')

>>> items2=items[:]

>>> ITEMS2

(' Nine Yang ', ' Big ship ', ' peace ', ' gold ')

>>>

Can the tuple change in disguise, the answer is yes.

>>> items2 = items2[:1]+ ("Baiyun Mountain",) +items2[1:]

>>> ITEMS2

(' Nine Yang ', ' Baiyun Mountain ', ' big ship ', ' peace ', ' gold ')

>>>

Python Learning Note 002_ array _ tuples