Getting started with Python programming to Practice-notes (1, 2)

Self-learning Python for some time, always feel that their foundation is not strong, think of the two books to read the basis of writing a blog to do a note what.

Be prepared to take a look again at "Getting started with Python programming to practice" and stick to blogging notes.

Getting started with Python programming to the first two chapters of the practice notes, learn the following:

View the Python version in the current environment

Building a Python environment

Names of variables and variables

Printing of strings

Modify the case of a string

Tabs and line breaks

Remove white space characters

A python integer operation that calculates the square, cubic

Use the str () function

View the Python version in the current environment

Enter Python at the command line to see the Python version installed in the current environment

My host is installed on the python3,windows under the installation strongly recommended through the Anacoda to install, really convenient. (You don't need to install Python separately, just one package is all done)

If you use Python2 to install a Ubuntu16.04 under a virtual machine, the version that comes with the system is python2.

In the Windows environment

The Ubuntu Environment

Variable

Define a variable: variable – Value

Store a value in the message variable Hello Python world! and print variables

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Message = "Hello Python world!"

Print (message)

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Hello Python world!

Variables can be defined repeatedly, but only the latest values are printed

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Message = "Hello Python world!" Print (message) message = "Hello Python Crash Course world!" Print (message)

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Hello Python world!

Hello Python Crash Course world!

Name of the variable:

1) Variable names can contain only letters, numbers, and underscores, but cannot start with a number.

2) The variable name cannot have spaces and can be connected using an underscore. Example: Beyond_soft

3) You cannot use Python's keyword and function name as a variable name. Example: Print

4) Try to use less than 1 and Q, not good distinction.

String:

The quotation marks in Python are all strings, which can be single quotes or double quotes.

Single quotation mark nested double quotation marks, double quotation marks nested single quotation marks, you can output the contents of parentheses normally (including the single \ double quotation marks in parentheses)

"Hello ' Python Crash ' Course world!"

' Hello ' Python Crash ' Course world! '

"Hello Python ' Carsh Course world!"

Modify the case of a string by using a system function

. Title () capitalize the first letter of the string

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name = "Ada Lovelace"

Print (Name.title ())

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Ada Lovelace

. Upper () capitalizes all the letters of a string

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name = "Ada Lovelace"

Print (Name.upper ())

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ADA LOVELACE

. lower () All lowercase letters of the string

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Name = "ADA LOVELACE"

Print (Name.lower ())

----------------------

Ada Lovelace

Merging strings

One thing to note in the merge string is the two double quotes in the following example.

Two double quotation marks in the middle with a space, printed as Ada Lovelace

If there are no spaces, print as Adalovelace

The + number is specifically used to connect variables and characters, and will not be printed

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first_name = "Ada"

last_name = "Lovelace"

Full_name = first_name + "" + last_name

Print (Full_name)

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Ada Lovelace

Reference the system function in print () and print

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first_name = "Ada"

last_name = "Lovelace"

Full_name = first_name + "" + last_name

Print ("Hello," + full_name.title () + "!")

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Hello, Ada lovelace!

Tabs and line breaks

TAB \ t: similar to Tab key

Line break \ n: Carriage return line

Note the following,

Tabs are not valid when they are in front of a line break

The tab effect is not printed because the tab is followed by a newline.

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Print ("Languages:\n\tpython\t\nc\t\njavascript")

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Languages:

Python

C

Javascript

Remove Blank

. Rstrip () Delete the last blank line of the string

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favorite_language = ' python '

Print (Favorite_language)

Print (Favorite_language.rstrip ())

Print (Favorite_language)

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Python #最后有一个空白字符

Python #最后无空白字符

python #最后有一个空白字符

You can also use the definition variable to cancel the trailing line of white space characters

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favorite_language = ' python '

Favorite_language = Favorite_language.rstrip ()

Print (Favorite_language)

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Python #最后无空白字符

Remove Whitespace characters summary

. Rstrip () Delete the trailing blank line

. Lstrip () Delete the beginning blank line

. Srtip () Delete blank lines at the beginning and tail lines

Integer arithmetic in python

Integer arithmetic of subtraction

>>> 2 + 3

5

>>> 5–3

2

>>> 2 * 4

8

>>> 8/4

2.0

Computes the square and cubic of integers

>>> 3 * * 2

9

>>> 6 * * 2

36

>>> 3 * * 3

27

>>> 2 * * 3

8

Use the str () function to avoid error types

To print numbers you need to specify the str () type

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Age = 23

message = "Happy" + str (age) + "rd birthday!"

Print (message)

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Happy 23rd birthday!

"Getting started with Python programming to Practice" 1th, Chapter 2 concludes.

Also hope to pass by the Daniel Generous enlighten, brother here thanked.

This article is from the "LULU" blog, make sure to keep this source http://aby028.blog.51cto.com/5371905/1964603

Getting started with Python programming to Practice-notes (1, 2)