第三章习题

3-1

将朋友姓名存储在列表中，依次将其打印

names = ['Yan Bin' 'Wang Yongfeng', 'Wu Ziyang']
for name in names:
    print(name)

浏览Python官网

Python官网整合了与Python有关的许多资源。其中包括源码、教程、文档、社区等，甚至还包括了成功案例和新闻时事。

Math

Align

\begin{align}
  f(x) &= x^2\\
  g(x) &= \frac{1}{x}\\
  F(x) &= \int^a_b \frac{1}{3}x^3
\end{align}

Matrix

\left[
\begin{matrix}
1 & 0\\
0 & 1
\end{matrix}
\right]

Picture

Add Picture

``` latex \usepackage{graphicx}

This article gives a thorough explanation on prototype chain. I assume the reader has a grasp of basic grammar in javascript and knowledge of object and function.
It’s good if you are familiar with an object-oriented language, but don’t be afraid if you don’t, as their techniques behind object are quite different.
Javascipt uses a techniques called prototype chainto implement inheritance. Before going into details, let’s review some basic points.

Define a Variable

To define a variable, simply use variable-name=value without and space.

$ a=5 # set a to 5
$ b = 5 # Opps, error
$ c=3+2 # Opps, does not work, 
        # which will be explained soon.

If you are interesting in the value stored in c in the third case above, you can try echo

$ echo $c
3+2

Strangely enough, it would output 3+2 instead of 5, far from our ideal behaviour.
The correct command to assign 5 to c would be discussed soon. As shown above, $ is uesd to refer to a variable.

$ echo a
a
$ echo $a
5
$ vim ${a}.cpp # equivelant to vim 5.cpp
               # {} can be ignored

Tree Kinds of Quote

Single Quote

A single quote will make anything inside it a plain text.

$ echo 'I am $USER, and today is `date`'
I am $USER, and today is `date`

Nothing will be translated.

Double Quote

Similar to single quote, double quote makes it a string. However, double quote allow $ to access to the variable and back quote to execute a command.

$ echo "I am $USER, and today is `date`"
I am yb, and today is 2017年 12月 01日 星期五 18:30:17 CST

Back Quote

Whatever inside the back quote(not a single quote!) would be treated as a command to run.

$ expr 4 + 2
6
$ a=`expr 4 + 2`
$ echo $a
6

run a shell

put your bar.sh to the path below
~/.local/bin and your script can be executed globally by current user.

Hello Blog

Hello blog.
Thanks to jekyll and github Page, as well as NexT which offers such an elegant template, I could build my blog in such a handy way.
vSpace means virtual space.

About Blog

I will be writing the blog in both Chinese or English, depending on my convenience. My notes, ideas, questions, or whatever I am currently doing would be post if it is worth a share.
Regular update is never guaranteed.

Blogs Organization

Blogs will be grouped by tags and category.
Tagindicates the language(s) the blog involvs, such as C, C++. A blog without tags is possible.
Categoryindicates the field it is mainly about, such as Operating System, Algorithm. Category is also optional.
Hopefully, it will save you (and I of course) a lot of time. Don’t forget to use the search function on the main menu (supported by NexT, thanks again). It is a poweful, quick and real-time search.