Python-based data types

Python-based data type string (string)

• Enclose a string in quotation marks, where the quotation marks can be single or double quotes

1. Use the method to modify the case of a string

例：>>> name = "ada lovelace">>> print name.title()Ada Lovelace>>> print(name.upper())ADA LOVELACE

2. Merging (stitching) strings

例：>>> first_name = "ada">>> last_name = "lovelace">>> full_name = first_name + " " + last_name>>> print full_nameada lovelace

3. Use tabs or newline characters to add blanks

例:>>> print("Python")Python>>> print("\tPython")    Python>>> print("\nPython\nhello")Pythonhello>>> print("\nPython\n\thello")Python    hello

4. Remove the end-to-end blanks

例：>>> message = ‘ python ‘>>> message‘ python ‘>>> message.rstrip()‘ python‘>>> message.lstrip()‘python ‘>>> message.strip()‘python‘    

Digital

1. Integer (int)

2. Floating point (float)

3. Long Integer type

4. Boolean type (BOOL)

5. Complex Type (complex)

Listing (list)

• A list consists of a series of elements arranged in a specific order, using square brackets ([]) to represent the list, and separating the elements with commas.

Access list elements, index starting from 0 instead of 1

例：>>> bicycles = [‘trek‘, ‘cannondale‘, ‘redline‘, ‘specialized‘]>>> print bicycles[0]trek>>> print bicycles[1]cannondale>>> print bicycles[-1]specialized

modifying, adding, and deleting elements

Example:>>> motorcycles = [' Honda ', ' Yamaha ', ' Suzuki ']>>> print motorcycles[' Honda ', ' Yamaha ', ' Suzuki '] modified >>> motorcycles[0] = ' Ducati ' >>> print motorcycles [' Ducati ', ' Yamaha ', ' Suzuki '] add >&G T;> motorcycles.append (' Ducati ') >>> print motorcycles [' Honda ', ' Yamaha ', ' Suzuki ', ' Ducati '] Append Just add elements at the end to insert elements in the list with insert () >>> motorcycles = [' Honda ', ' Yamaha ', ' Suzuki '] >>> motorcycles.ins ERT (0, ' Ducati ') >>> print motorcycles [' Ducati ', ' Honda ', ' Yamaha ', ' Suzuki '] Delete the Del method----use the DEL statement to delete the value from the list    In addition, you will no longer be able to access it >>> del motorcycles[0] >>> print motorcycles [' Yamaha ', ' Suzuki '] Pop () method    1. Delete the last element of the list >>> Motorcycles.pop () ' Suzuki ' >>> print motorcycles [' Honda ', ' Yamaha '] 2. Specify element deletion >>> motorcycles.pop (0) ' Honda ' >>> print motorcycles [' Yamaha ', ' Suzuki '] Remov The E () method----Delete the first specified value

Organization List (sort)

1. Use the method sort () to sort the list in a permanent order

例：>>> cars = [‘bmw‘, ‘audi‘, ‘toyota‘, ‘subaru‘]>>> cars.sort()>>> print cars[‘audi‘, ‘bmw‘, ‘subaru‘, ‘toyota‘]反向排序----sort()传递参数reverse=True>>> cars.sort(reverse=True)>>> print cars[‘toyota‘, ‘subaru‘, ‘bmw‘, ‘audi‘]

2. Use the function sorted () to sort the list 临时

• When the function sorted () is called, the order of the list elements is not changed

3. Reverse the Print List

例：>>> cars = [‘bmw‘, ‘audi‘, ‘toyota‘, ‘subaru‘]>>> cars.reverse()>>> print cars[‘subaru‘, ‘toyota‘, ‘audi‘, ‘bmw‘]

4. Length of the list

>>> cars = [‘bmw‘, ‘audi‘, ‘toyota‘, ‘subaru‘]>>> len(cars)4

Action list

1. Traverse the entire list

例：>>> cars = [‘bmw‘, ‘audi‘, ‘toyota‘, ‘subaru‘]>>> for car in cars:...     print car...bmwauditoyotasubaru

2. Create a list of values

① using function range ()

例：>>> for i in range(1,5):...     print i...1234

② using range () to create a list of numbers

例： >>> num = list(range(1,5))>>> print num[1, 2, 3, 4]

3. Perform simple statistics on a list of numbers

例：>>> digits = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0]>>> min(digits)0>>> max(digits)9>>> sum(digits)45

Use part of a list

1. Slicing

例：>>> players = [‘charles‘, ‘martina‘, ‘michael‘, ‘florence‘, ‘eli‘]>>> print players[1:3][‘martina‘, ‘michael‘]

2. Traversing slices

例：>>> players = [‘charles‘, ‘martina‘, ‘michael‘, ‘florence‘, ‘eli‘]>>> for player in players[:3]:...     print player.title()...CharlesMartinaMichael

Tuples (TUPE)

• Immutable lists are referred to as tuples
• Tuples look like lists, but use parentheses instead of square brackets to identify
• Tuple operations are the same as lists

modifying tuple elements

element values in tuples are not allowed to be modified, but we can concatenate combinations of tuples

例：>>> t = (12, 13, 14, 15, 21, 22 )>>> t1 = t[0:3]>>> t2 = (19,)>>> t3 = t[4:]>>> t = t1 + t2 + t3>>> print t(12, 13, 14, 19, 21, 22)

Delete a tuple element

例：>>> t = (12, 13, 14, 15, 21, 22 )>>> t1 = t[0:3] + t[4:]>>> t = t1>>> print t(12, 13, 14, 21, 22)

Dictionary (dict)

• A dictionary is another mutable container model and can store any type of object
• Each key value of the dictionary (key=>value) pairs with a colon (:) split, each pair is separated by a comma (,), and the entire dictionary is included in curly braces ({})

Accessing dictionaries

例：>>> dict = {‘Name‘: ‘Runoob‘, ‘Age‘: 7, ‘Class‘: ‘First‘}>>> print dict[‘Name‘]Runoob

Modify Dictionary

例：>>> dict = {‘Name‘: ‘Runoob‘, ‘Age‘: 7, ‘Class‘: ‘First‘}>>> print dict{‘Age‘: 7, ‘Name‘: ‘Runoob‘, ‘Class‘: ‘First‘}>>> dict[‘Age‘] = 11>>> print dict{‘Age‘: 11, ‘Name‘: ‘Runoob‘, ‘Class‘: ‘First‘}

Delete an element in a dictionary

例：>>> dict = {‘Name‘: ‘Runoob‘, ‘Age‘: 7, ‘Class‘: ‘First‘}>>> del dict[‘Name‘]>>> print dict{‘Age‘: 7, ‘Class‘: ‘First‘}

Collection (SET)

• Sequence of unordered non-repeating elements
• The basic function is to test the membership and remove duplicate elements
• You can create a collection using curly braces ({}) or set () functions

Note: Creating an empty collection must be set () instead of {}, because {} is used to create an empty dictionary

例：>>> student = {‘Tom‘, ‘Jim‘, ‘Mary‘, ‘Tom‘, ‘Jack‘, ‘Rose‘}>>> print studentset([‘Mary‘, ‘Rose‘, ‘Jim‘, ‘Jack‘, ‘Tom‘])

Python-based data types