1_1_python-course-notes-sections-1-7.pdf
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This document provides an overview and introduction to learning Python. It discusses Python programming concepts like data science, machine learning, data visualizations, and web development. It also outlines benefits of Python like job opportunities, large community, being cross-platform, and free. The document then describes the Anaconda distribution tool for scientific computing projects. It introduces the Spyder IDE and its features like source code area, IPython console, and variable/file explorers. Basic Python syntax is covered such as printing, strings, variables, and conditionals. Finally, it discusses lists, loops, and common list methods.
![More on strings
This is how string indexing from a coding perspective looks like.
len(my_string)
my_string[0]
my_string[1:4]
NB:
1. Python is a zero-
indexing program language
This means that Python starts
counting from 0 and that’s why
if we type [1] – Python will give
us the letter Y.
2. In Python:
‘n’ == ‘N’
False
P Y T H O N
1 2 3 4 5
0 6
Shows the length of the string
Python = 6 (It has 6 letters)
Meaning: From this string, please give me the first character
Python = P
Meaning: Give me access to group of letters that start at the
first index to the fourth
Python = yth
Our variable: my_string
⇢ It points to a space in the main memory.
⇢ That space contains the string Python
⇢ Each of Python’ s letters has its own unique space
⇢ We can access these letters by using the index numbers ⇢
my_string.upper ( )
Capitalizes all letters. Lower makes all letters lower case.](https://image.slidesharecdn.com/11python-course-notes-sections-1-7-220809033911-18546bad/85/1_1_python-course-notes-sections-1-7-pdf-11-320.jpg)
![Lists and Loops
Code Block Run
Repeat Tasks
(Loop)
</>
END
Types of Loops:
For Loops ⇢ Repeat a certain number of times
While Loops ⇢ Repeat based on a condition (True/False)
1
2
Computers are good at doing repetitive tasks quickly
NB:
Incrementing values:
Changing the value of a variable
List Example:
m y _ l i s t = [ 3 4 , 7 6 , 5 8 ]](https://image.slidesharecdn.com/11python-course-notes-sections-1-7-220809033911-18546bad/85/1_1_python-course-notes-sections-1-7-pdf-12-320.jpg)
1_1_python-course-notes-sections-1-7.pdf
- 2. ⇢ Data Science ⇢ Machine Learning ⇢ Data Visualizations ⇢ Data Applications ⇢ Web Development Python is good for: ⇢ A lot of job opportunities ⇢ Large Python community ⇢ Cross platform ⇢ Completely Free ⇢ A lot of built-in functionalities More benefits: ⇢ Academia ⇢ Industry Python is used in: Why Python?
- 3. 3 Steps Python Installation Supported by a vibrant community of open-source contributors, Anaconda Distribution is the tool of choice for solo data scientists and machine learning enthusiast, who want to use Python for scientific computing projects. 01 02 03 Click on Download Step 2 Choose Python 3 version Step 3 Go to www.anaconda.com Step 1
- 4. Introducing Spider Integrated Development Environment It has: ⇢ Source code area ⇢ Highlighted syntaxis ⇢ A place for running code IDE Contains: ⇢ File editor ⇢ IPython Console ⇢ Variable explorer, File explorer and Help box Spyder Spyder is a powerful scientific environment written in Python, for Python, and designed by and for scientists, engineers and data analysts. It offers a unique combination of the advanced editing, analysis, debugging, and profiling functionality of a comprehensive development tool with the data exploration, interactive execution, deep inspection, and beautiful visualization capabilities of a scientific package. Beyond its many built-in features, its abilities can be extended even further via its plugin system and API. Furthermore, Spyder can also be used as a PyQt5 extension library, allowing developers to build upon its functionality and embed its components, such as the interactive console, in their own PyQt software
- 5. Printing in a Nutshell In Jupyter and Spyder, the last line in the input field is returned as an output (if there is anything to display). Therefore to display an operation we can either write as the last line in the input field or use the print function. Name error ⇢ always indicate the string of characters with single or double quotation marks (Word) (Hi) end=’ ’ Defines an end character for a string . By default the end character is a new line. end=’ ’ Always gives a decimal number called Floating Point Number (Float) Forward Slash / // Always gives an integer value and discards the decimal part 2 Forward Slashes ** To the power of 2 Asterisks ’ ’ Creates a string Single Quotation Marks clear Clears the console. Clear Python Syntax Whenever we are dealing with the print ( ) function, we can force the display of the operations If we are printing a string, we’ve got some some extra characters to help us n New line Backward Slash + n t Indents the text, Tab command Backward Slash + t Escapes the following character. Backward Slash
- 6. Variables: General Rules Variables can’t start with number. We can’t have space in a variable’s name. ! However, we can have underscores. 01 02 We can change variable’s values. 03 Giving the variables sensible names is a good practice. 04 A variable can be set equal to a string. (String concatenation) 05 Asking the computer for more space in the main memory 1x=3 new_variable = 3 z = x + y z = x - y area=pi*radius**2 phrase_1 + phrase_2
- 7. Strings: Input Function Allows you to get user’s input Keywords: Returns the type of a value ⇢ str = string ⇢ int = integer Input(’string’) The user is requested to make an input If we press “Enter” ⇢ The input function has finished running They are not allowed to be used as variables names. To access the list with the keywords, type in the console: ⇢ help () ⇢ keywords Type: Symbol: # ⇢ highlight the area ⇢ right click ⇢ Comment/Uncomment NB: Comment/Uncomment:
- 8. Conditionals: Boolean Expressions Conditionals are what allow computers to make decisions based on the value of variables. Python can check weather a statement is true or false. Conditionals in real life Example Don’t Buy IF Don’t have money Have money Buy IF Want Don’t Want == != <= >= Checking for equality Not equal to Less than or equal to Grater than or equal to
- 9. Logical operators If both conditions are satisfied ⇢ True And Or Negates the result of the condition Not True ⇢ False Not False ⇢ True Not AND OR NOT Logical operators chain Boolean expressions together to give a particular result If only one variable satisfies the condition ⇢ True Is 15 < 22 or 22 < 22 ⇢ True is 15 < 22 and 20 < 22 ⇢ True not( 20 < 22 and 25 < 22) ⇢ True not( 20 < 22 or 25 < 22) ⇢ False
- 10. If Statement Python supports the usual logical conditions from mathematics. These conditions can be used in several ways, most commonly in "if statements" and loops. some_condition = False if some_condition: print(‘The variable ‘some_condition’ is True’) else: print(‘The variable ‘some_condition’ is False’) Our variable If statement Else statement NB: You can use elif statement if you want to check more than one condition Meaning: If this condition evaluates to True, then print the following line of code. Meaning: In every other case, print something else If, else and print are colored in blue, because they are keywords.
- 11. More on strings This is how string indexing from a coding perspective looks like. len(my_string) my_string[0] my_string[1:4] NB: 1. Python is a zero- indexing program language This means that Python starts counting from 0 and that’s why if we type [1] – Python will give us the letter Y. 2. In Python: ‘n’ == ‘N’ False P Y T H O N 1 2 3 4 5 0 6 Shows the length of the string Python = 6 (It has 6 letters) Meaning: From this string, please give me the first character Python = P Meaning: Give me access to group of letters that start at the first index to the fourth Python = yth Our variable: my_string ⇢ It points to a space in the main memory. ⇢ That space contains the string Python ⇢ Each of Python’ s letters has its own unique space ⇢ We can access these letters by using the index numbers ⇢ my_string.upper ( ) Capitalizes all letters. Lower makes all letters lower case.
- 12. Lists and Loops Code Block Run Repeat Tasks (Loop) </> END Types of Loops: For Loops ⇢ Repeat a certain number of times While Loops ⇢ Repeat based on a condition (True/False) 1 2 Computers are good at doing repetitive tasks quickly NB: Incrementing values: Changing the value of a variable List Example: m y _ l i s t = [ 3 4 , 7 6 , 5 8 ]
- 13. Common List Methods It appends the desired value at the end of the list Append It reverses the order of the list Reverse This method shows the index of the value Index Similar to Append. We can add a whole new list to the current list. Extend Removes values from the list Remove *It could be useful in For Loops If you write the name of the variable (e.g. my_list) and then type . (dot) all of the methods that are available will appear. Modolo Operator 11 % 2 Result: 1 Modulus gives you the remainder of the result of the division It’s denoted by the % sign m y _ l i s t .