From da3aa14cee5ef4308f913bee54183b2e6f33d9dc Mon Sep 17 00:00:00 2001
From: weilun ong <weilun@gmail.com>
Date: Tue, 27 Apr 2021 09:29:08 +0800
Subject: [PATCH] addded lessson summary

---
 lesson_summary/python/REPL.md     | 46 +++++++++++++++++++++++++++++++
 lesson_summary/python/comments.md | 37 +++++++++++++++++++++++++
 2 files changed, 83 insertions(+)
 create mode 100644 lesson_summary/python/REPL.md
 create mode 100644 lesson_summary/python/comments.md

diff --git a/lesson_summary/python/REPL.md b/lesson_summary/python/REPL.md
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+###Introducing the REPL for Rapid Experimentation
+
+Python is an interpreted language, and the code is evaluated line-by-line. 
+Each line can be evaluated by itself, and this allows us to have a REPL.
+
+
+What is a REPL?
+
+>REPL stands for: Read, Evaluate, Print, Loop
+
+>Each line is read, evaluated, the return value is then printed to the screen, 
+and then the process repeats.
+
+>Python ships with a REPL, and you can access it by running python3.6 from your terminal.
+
+Eg.1: 
+$ python3.6
+Python 3.6.4 (default, Jan 5 2018, 20:24:27)
+[GCC 4.8.5 20150623 (Red Hat 4.8.5-16)] on linux
+Type "help", "copyright", "credits" or "license" for more information.
+>>>
+
+Expln 1:
+The >>> indicates that you can type on that line. Later on, you’ll also see a ... which 
+means that you are currently in a scoped area and will need to enter a blank line (no spaces) 
+before it evaluates the entire code block.
+
+The simplest use of this would be to do some math:
+
+Eg.2:
+>>> 1 + 1 
+2
+>>>
+
+Expln 2:
+2 is the return value of the expression, and it is then printed to the screen. If something
+doesn’t have a return value, then nothing will be printed to the screen and you’ll see the 
+next prompt immediately. We’ll cover this later, but an example would be None:
+
+Eg.3: 
+>>> None
+>>>
+
+
+Lastly, to exit the REPL, you can either type exit() (the parentheses are important), or you
+can hit Ctrl+d on your keyboard.
diff --git a/lesson_summary/python/comments.md b/lesson_summary/python/comments.md
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+ ###Lesson Description - Using Comments
+
+When writing scripts, we often want to leave ourselves notes or explanations. 
+Python (along with most scripting languages) uses the # character to signify
+that the line should be ignored and not executed.
+
+
+
+Single Line Comment
+
+We can comment out a whole line:
+
+  Eg. 1  # This is a full like comment
+
+or we can comment at the end of a line:
+
+  Eg. 2  2 + 2 # This will add the numbers
+
+
+
+
+
+What About Block Comments?
+
+Python does not have the concept of block commenting that you may have encountered 
+in other languages. Many people mistake a triple-quoted string as being a comment, 
+but it is not, it’s a multi-line string. That being said, multi-line strings can 
+functionally work like comments, but they will still be allocated into memory.
+
+  Eg. 3
+"""
+This is not a block comment,
+but it will still work when you really need 
+for some lines of code to not execute.
+"""
+  
+