Python Data structure

2017-06-24 14:34:39

1, integers and long integers

2. Floating point number

3, plural, shape such as 1+4j, etc.

4, string single quotation marks can be, there are three quotation marks, the function of three quotation marks to achieve the operation of multi-line string

Common functions:

Len (): Gets the length of the string

5. List

Hit the array of hormones, compared to the C + + array, the list is more powerful, no data type, can be put in. The list is a mutable data type, such as: a=[0,1,2,3]

Access elements and arrays consistent, list[0] ..., the subscript value can be negative, list[-1] represents the last number, list[:] Represents a copy of the whole, list[:-1] represents the slice except the last number

At the same time can be sliced list[0:3], is still the front open after closed, that is, only 0,1,2, similar to MATLAB

You can use the for item in list: to traverse the list

A list is a sequence

Common functions:

. Len (): List length

. Append (): Add an element at the end

. Extend (): parameter type is a list, add multiple elements at the end

. Insert (Pos,key): Add key at POS location

. Remove (key): Delete the first key

Del list[0]: You can delete the entire list by following the subscript

6, tuple tuple

Ganso and lists are very similar, but the progenitor is immutable

Ganso General representation is a= (all-in-one), the comma is the root of the identity tuple, and if you remove (), its data type remains a tuple

Elements of tuples cannot be modified or deleted.

Empty tuple a= ()

A= (1,) with only one element, comma essential

One example of a specific use of tuples is the print function

" Timhy "  =print("age of%s is%d" % (name,age))

A tuple is a sequence

7. Dictionary Dict

Similar to the map in the STL, the use of the Key,value storage form, the specific form: a={' A ' =1, ' B ' =2, ' c ' = 3}

The addition of dictionaries is also the same as map, i.e. a[' d ']=4

The deletion of the dictionary is the same as list, using the index value to complete the delete operation, Del a[' a ']

You can use the for Aipha,number in A.items (): To complete the traversal

Some of the other built-in functions:

Type (): Used to determine the type of variable

Isinstance () Function: Judging data type
Isinstance (520,int) gets True

Python Data structure