1. PYZO ENVIRONMENT (http://www.pyzo.org/)

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interactive shell block of code (ctrl + E to compile, ctrl + S to save) python 3.4.1 (also has to be installed (to check: run cmd -> python -V))

2. VARIABLES
Variables are nothing but reserved memory locations to store values. This means that when you create a variable you reserve some space in memory.

2A: Assigning Values to Variables
The equal sign (=) is used to assign values to variables.
apples = 11 berries = 45 bus = 20 train = 52.56

Textual values are inside quotes:
word = 'hello' sentence = 'Hello world, this is sentence.'

Not allowed values:
# mixing wrong1 = wrong2 = wrong3 = # … wrong4 wrong5 wrong6 wrong6 number with textual value 'hello'45 12men 7'apples'

= = 'hello = 158 597 = 158,597 # should be 158.597

Not allowed names:
12train = 'variable starting with number' train-variable = 'variable name with special symbol' hi there = 'variable with two words'

Allowed names:
train11 = 'number not in the beginning' my_variable = 'variable name with underscore (only allowed symbol)' myVariable = 'camelCase naming'

3. BASIC COMMANDS
3A: Print
Outputs to command line without a variable
print('hello world') print('ID485454?asd, aaabbcc') print (''' There's something going on here. With the three double-quotes. We'll be able to type as much as we like. Even 4 lines if we want, or 5, or 6. ''')

debugging informative purposes

printing textual variable (more possible ways)
fruit = 'banana' print (fruit) print ('favourite fruit: ' + fruit) number_of_apples = 12 print ('Hi, I have', number_of_apples, 'apples.' ) fruit = 'banana' number_of_apples = 12 print ('my favourite fruit is %s, but I have %s apples.' %(fruit, number_of_apples))

3B: Input
Getting data from user
person = input('Enter your name: ') print('Hello', person) # print converts values to strings! number_of_apples = input('How many apples do you have?') print('Hello', person ,',you have' , number_of_apples ,'apples.') # number_of_apples

3C: Comments
Information purposes, annotating code
# this code will be about fruits fruit = 'banana' # this is my favourite fruit

4. NUMBERS (https://docs.python.org/3/library/stdtypes.html#numeric-types-intfloat-complex)

4A: Numerical types
int (signed integers): They are often called just integers or ints, are positive or negative whole numbers with no decimal point. float (floating point real values) : Also called floats, they represent real numbers and are written with a decimal point dividing the integer and fractional parts. Floats may also be in scientific notation, with E or e indicating the power of 10 (2.5e2 = 2.5 x 102 = 250).

litres_of_milk1 = 2.17 # float litres_of_milk2 = 3.77 # float number_of_people = 3 # integer

Converting numerical types with int() and float()
float(number_of_people) int(litres_of_milk)

4B: Doing math
basic operations:
print print print print (2 + 3) # addition (2.14 - 0.58) # subtraction (2 * 1.78) # multiplication (5.14 / 3) # division

other operations:
# negation money_yesterday = 120 money_missing = -money_yesterday # modulo - remainder after division apples = 27 apples_for_pie = 5 apples_not_used = apples % apples_for_pie # exponent, square root square1_edge = 2 square1_area = pow(square1_edge, 3) # also square1_edge ** 2 square2_area = 3 square2_edge = pow(square2_area, 0.5) # increment, decrement region_inhabitants = 1532 region_inhabitants += 29 # immigration, region_inhabitants = 1561 region_inhabitants -= 15 # emigration, region_inhabitants = 1546

comparing numbers:
coef1 = 2.145 coef2 = 1.245 coef3 = 0.475

print print print print

(coef1 (coef1 (coef3 (coef3

> coef2) <= coef3) # smaller or equal = coef2) # equal ! != coef2) # not equal

4C: Number methods
rounding round()
# round to integer invited_people = 157 inviting_effectivity = 0.43 expected_people = round(invited_people * inviting_effectivity) # rounding to decimal points two_decimals = round(12.131321, 2)

# 12.13

maximum max(), minimum min()
region1 = 156 region2 = 17 region3 = 478 region4 = 69 regions_max = max(region1, region2, region3, region4) regions_min = min(region1, region2, region3, region4)

...

5. STRINGS

(https://docs.python.org/2/library/string.html)

variables with textual value

5A: String values
setting values, getting substrings with []
a_string = 'hello world!' print (a_string ) # hello world! print ('value of my string is', hello_string) # getting substring (index 0 ~ position 1 !) print (a_string[0]) # h -> character at index 0 print (a_string[-1]) # ! -> first character from the end print (a_string[0:5]) # hello -> characters at indexes 0 to 5

string operators
# in returns true if a character exists in the given string

a_string = 'hello world!' print ('a' in a_string) # False print ('hello' in a_string) # True # merging strings with + a = 'hello' b = 'world!' print (a + b) # helloworld # repetition with * a = 'hello' print (a * 4) # hellohellohellohello

comparing strings:
name = "Bob" print (name == "Alex") # False

5A: String methods
(https://docs.python.org/3/library/stdtypes.html#string-methods)
find()
# find() returns position of substring or -1 hello_string = 'hello world!' print (hello_string.find('a')) # -1 print (hello_string.find('l')) # 2 print (hello_string.find('hello')) # 1 # second (starting index) and third (ending index) parameter print (hello_string.find('l', 4)) # 9 print (hello_string.find('o', 0, 5)) # 4

count()
# count() return number of occurences hello_string = 'hello world!' print (hello_string.count('l')) # 3

isnumeric()
# isnumeric() return true if string contains only numeric characters text_string = 'hello world!' number_string = '1547854' print (text_string.isnumeric()) # False print (number_string.isnumeric()) # True

len()

# number of characters in string returns len() example_string = 'a c' print(len(example_string)) # 18

replace()
# replace changes substrings example_string = 'hello world!' print(example_string.replace('world', 'python')) #hello python!

6. BOOLEANS
Boolean values are the two constant objects False and True bool()
# bool will evaluate 0, number1 = 0 number2 = 0.0 number3 = 15 print (bool(number1)) # print (bool(number2)) # print (bool(number3)) # text1 text2 print print empty string or None value as False

False False True

= 'hello' = '' (bool(text1)) # True (bool(text2)) # False

nothing = None print (bool(nothing)) # False

7. CONVERSION OF DATA TYPES
# int() converts to integer number print (int(21.75)) # 21 print (int('456')) # 456 print (int(False)) # 0 # float() print (float('1.2456')) # 1.2456 print (float(12)) # 12.0 print (float(True)) # 1.0 # str() print (str(12)) # '12' print (str(False)) # 'False' # bool()

print print print print

(bool(-1)) # True (bool('hallo')) # True (bool('')) #False (bool(0)) #False

Motivation:
# problems with combination of data types a_string = "blabla" a_number = 15 print (a_string + a_number) # TypeError