# 2 [python3] Separation and comment out

Introduction

This article is written by a fledgling engineer who has been studying programming for about two months for the purpose of output. After biting ruby and js, I became interested in the trend python, so I started learning. In this article, I'll write about delimiters and comment outs. It will be a short article, but I would appreciate it if you could point out any points you are interested in! This article is based on the assumption that python3 and anaconda are installed on macOS.

1 Statement (instruction statement) delimiter

The program code also needs to be separated for each punctuation mark "." In Japanese and the period "." In English. In the case of Japanese or English, it is possible to read even if there is no delimiter in the sentence, but in the case of program code, an error will occur if the delimiter is not inserted correctly.

** Error if not separated correctly **

test.py

hige = 1 * 5 hoge = 2 * 2 print(hige) print(hoge)

↑ in the terminal

$ python test.py
  File "test.py", line 1
    hige = 1 * 5 hoge = 2 * 2 print(hige) print(hoge)
                 ^
SyntaxError: invalid syntax

SyntaxError: invalid syntax means syntax error in Japanese. This error is easy to resolve. There are two main methods, so I will introduce them.

** ①; How to separate with ** The first is to separate them with a semicolon. I will actually try it.

test.py

hige = 1 * 5 ; hoge = 2 * 2 ; print(hige) ; print(hoge)

↑ in the terminal

$ python test.py
5
4

I was able to resolve the error by separating the statements with; in this way.

** ② How to separate with line breaks ** The second method is to separate them with line breaks. I will actually try this as well.

test.py

hige = 1 * 5
hoge = 2 * 2 
print(hige)
print(hoge)

↑ in the terminal

$ python test.py
5
4

I was able to execute this without causing an error. Then, which one should I separate? I think some people think that, but if you develop it individually, you can decide it completely according to your preference. If the rules are set by the company or team you belong to, I think you will follow them.

2 Comment out

The comment-out function is indispensable when annotating the code and checking the operation, so it is a place to remember. I will introduce two this time.

** ① How to use # ** You can comment out by adding # at the beginning of the sentence. Let's actually annotate the code.

test.py

hige = 1 * 5 #This is 1 to hige*Substituting 5

print(hige)

I was able to annotate the code. The statement after the # does not affect the execution of the code.

** How to use ② "** "You can comment out all at once by enclosing the sentence with three.

test.py

hige = 1 * 5 
"""
↑ is 1 for hige*Substituting 5.
Inside double quotes does not affect code execution.
This is useful when you want to comment out over multiple lines.
"""
print(hige)

At the end

This is the end of this article. I want to make good use of delimiters and comment outs and try to write code that is easy to read! Next article → https://qiita.com/shin12032123/items/89ecbff9257833eceff3