(r5) REPLAndStandardPythonProgramming < IoT_Course

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<p align="center"><font face="Liberation Sans, sans-serif"><font size="6"> *Course on Internet of Things* </font></font></p>
---+ Exercises Session 1:
---++ Introductory remarks:

The scripts we are going to develop during this exercise session do not depend on any system issues: We do not use command line arguments not available in !MicroPython nor do we use any hardware specific features which are not available on a PC. The exercises can therefore be developed and run on the ESP32 but also on any standard PC with Python3 installed.
---++ Exercise 1: Use of REPL

Connect to your ESP32 with minicom or thonny. You may try the same thing running Python3 on your PC.

Using REPL:
   * <p>print “Hello World!”</p>
   * <p>read in a text using <i>input() </i>and print it</p>
   * <p>Calculate</p> <p><img align="middle" alt="calculations.png" height="52" src="%PUBURL%/UCC_Course_2020/Exercises/calculations.png" title="calculations.png" width="142" /></p>
   * <p>Calculate sin(30°) <br /> If you see errors, how do you correct them? Are the results correct?</p>
   * Finally make the "print Hello World!" command a script and execute it.
---++ Exercise 2: A simple calculator

Write a script that assigns the values 5 and 3 to the variables a and b respectively

Print the results of 4 basic arithmetic operations:
   * <p>a+b</p>
   * <p>a-b</p>
   * <p>a*b</p>
   * <p>a/b</p>
Which result do you observe for division? Can you correct?

Improve this program asking the user to enter 2 real numbers (floats) separated by a space. This is how it should look like:

<img alt="calcOk.png" height="172" src="%ATTACHURL%/calcOk.png" title="calcOk.png" width="845" />

If this happens:

<img alt="conversionError.png" height="150" src="%ATTACHURL%/conversionError.png" title="conversionError.png" width="636" />

when the user mistypes and enters something that is not an integer, can you capture the error and simply ask the user to repeat his input, until you get 2 correct integer numbers?

*Bonus points:* Writing a parser for user input is rather easy if the numbers and operator are separated by spaces (have a look at the split method of strings). It is quite a bit more tricky if you allow entering calculations without spaces between the operands and the operator. Can you write a parser accomplishing this?

Try your parser on this input:
| *Input* | *ok or not ok* |
| 5.3+4.7 | ok |
| 5.3++4.7 | not ok |
| 5..3 + 4.7 | not ok |
| .3+.7 | ok |
| 5.3+4b7 | not ok |
| empty string | not ok |
| 5.3+. | not ok |
Try also several spaces in between operands and operator.
---++ Exercise 3: Conditions

Like in exercise2, start with 2 numbers a,b with values 5 and 3. In your program check which of the 2 numbers is bigger and print the result.

Then improve the program asking the user for 2 integer numbers. Make sure he enters 2 correct numbers and capture possible errors. This is a typical output:

<img alt="conditions.png" height="188" src="%ATTACHURL%/conditions.png" title="conditions.png" width="649" />
---++ Exercise 4: The Fibonacci series

The Fibonacci number series is defined as:

F(0) = 0; F(1) = 1

F(n) = F(n-1) + F(n-2)<br /><br />
   * Calculate and print out the Fibonacci numbers up to F(n). Get n from the user where n &gt;= 0
Try your program for n=0, n=1, n=2, n=3, n=20<br /><br />
   * Ask the user up to which is the maximum number up to which you should calculate.
---++ Exercise 5: Some maths: Calculate the sine function

Write a script that asks the user for an angle in degrees. Calculate the sine of this angle.
---++ Exercise 6: Classes

Write a Python class with methods calculation mathematical number series. These series should be calculated:
   * The Fibonacci numbers up to F(n). n is passed as parameter to the method
   * The Fibonacci numbers smaller than max. max is passed as parameter to the method
   * The prime numbers up to max
   * Factorial:<br /><img alt="factorial.png" height="41" src="%ATTACHURL%/factorial.png" title="factorial.png" width="308" />
   * The geometric number series:<br /><img alt="geometric.png" height="72" src="%ATTACHURL%/geometric.png" title="geometric.png" width="335" />
   * The harmonic number series:<br /><img alt="harmonic.png" height="72" src="%ATTACHURL%/harmonic.png" title="harmonic.png" width="76" />
 <br />Can you tell what the following series calculate?
| <img alt="ln2.png" height="74" src="%ATTACHURL%/ln2.png" title="ln2.png" width="117" /> | <img alt="pi.png" height="74" src="%ATTACHURL%/pi.png" title="pi.png" width="141" /> | <img alt="e.png" height="70" src="%ATTACHURL%/e.png" title="e.png" width="94" /> |
Add these series to your class and try. Write a test script exercising the different methods.

When running on a PC you may want to plot the series as well.

-- %USERSIG{UliRaich - 2020-05-03}%

---++ Comments

%COMMENT%

Attachments

Topic attachments
I	Attachment	History	Action	Size	Date	Who
png	calcOk.png	r1	manage	21.7 K	2020-05-03 - 19:52	UliRaich
png	conditions.png	r1	manage	28.8 K	2020-05-03 - 20:25	UliRaich
png	conversionError.png	r1	manage	19.3 K	2020-05-03 - 19:42	UliRaich
png	e.png	r1	manage	1.9 K	2020-05-04 - 12:56	UliRaich
png	factorial.png	r1	manage	2.8 K	2020-05-04 - 12:48	UliRaich
png	geometric.png	r1	manage	3.9 K	2020-05-04 - 12:48	UliRaich
png	harmonic.png	r1	manage	1.6 K	2020-05-04 - 12:53	UliRaich
png	ln2.png	r1	manage	2.0 K	2020-05-04 - 12:48	UliRaich
png	pi.png	r1	manage	2.7 K	2020-05-04 - 12:48	UliRaich

Topic revision: r5 - 2020-05-04 - UliRaich