Notes and learnings from Kaggle (Intro to Programming)
Intro to programming
Arithmetic and Variables
Shift + Enter to run a code
removing # sign is called uncommenting
print("Hello, world")
print(1+2)
print(3**2)
print(((1 + 3) * (9 - 2) / 2) ** 2)
#Multiply 3 by 2
print(3*2)
Multiply 3 by 2
#create test_var and give value
test_var = 4+5
#print the value
print(test_var)
# set the value 3
my_var = 3
#print the value my_var
print(my_var)
#Set the new value 100
my_var = 100
#print the new my_var
print(my_var)
print(my_var)
print(test_var)
my_var = my_var + 3
#Increase value by 3
my_var = my_var + 3
#print the increased value
print(my_var)
num_years = 4
days_per_year = 365
hours_per_day = 24
seconds_per_hour = 60
secs_per_year = 60
#Calculate umber of seconds of 4 year
total_secs = secs_per_year * seconds_per_hour * hours_per_day * days_per_year * num_years
#print result
print(total_secs)
num_years = 4
days_per_year = 365
hours_per_day = 24
seconds_per_hour = 60
secs_per_year = 60
#update the days per year
days_per_year = 365.25
#Calculate new total_secs
total_secs = secs_per_year * seconds_per_hour * hours_per_day * days_per_year * num_years
print(total_secs)
NameError: print(hours_per_dy)
Functions
function starts with def
argument name will be input_var
the parentheses of function argument(s) need to end by a colon :
#Define the function
def add_three(input_var):
output_var = input_var + 3
return output_var
#Run the function with 10 as input
new_number = add_three(10)
print(new_number)
def get_pay(num_hours):
#pre_taxpay, based on receieving 15/- per hour
pay_pretax = num_hours * 15
#after tax pay, based on 12% cut on tax
pay_aftertax = pay_pretax * (1-.12)
return(pay_aftertax)
#Calculate pay based on working 40 hours
pay_fulltime = get_pay(40)
print (pay_fulltime)
Data Types
different data types, such as
integers
numbers without any fractional part and can be positive/negative/zero
variable x
verify the data type= 'type()'
variable name in parantheses
-
x=14
print (x)
print (type(x))
<class 'int'> refers to the integer data type.
------------------
floats
numbers with fractional parts
nearly_pie = 3.141592653
print (nearly_pie)
print (type (nearly_pie))
almost_pie = 22/7
print (almost_pie)
print (type(almost_pie))
<class 'float'> means floats data type.
round() function is useful to round a number.
#round to 5 decimal places
almost_pi = 3.14159
rounded_pi= round(almost_pi, 5)
print (rounded_pi)
print(type(rounded_pi))
y_float = 1.
print (y_float)
print (type(y_float))
Output: 1.0
<class 'float'>
Booleans (True/False)
z_one = True
print (z_one)
print (type(z_one))
Output: True
<class 'bool'>
z_two = False
print (z_two)
print (type(z_two))
Output: False
<class 'bool'>
z_three = 1 < 2
print (z_three)
print (type(z_three))
Output: True
<class 'bool'>
z_four = 5 < 3
print(z_four)
print (type(z_four))
Output: False
<class 'bool'>
z_five = not z_four
print (z_five)
print(type(z_five))
Output: True
<class 'bool'>
Strings
collection of characters (like alphabet letters, punctuation, numerical digits, or symbols)
comes in quotation mark
generally used to present text
w = 'Hello! Python'
print (w)
print(type(w))
print(len(w))
Output: Hello! Python
<class 'str'>
14
shortest_string = ""
print (type(shortest_string))
print(len(shortest_string))
Output: <class 'str'>
0
shortest_string = ""
print (type(shortest_string))
print(len(shortest_string))
Output: <class 'str'>
0
#string to float number
y_number ='2.321'
also_my_number = float (my_number)
print (my_number)
print (type(my_number))
Output: 2.321
<class 'str'>
#add two strings
new_string = 'abc' + 'def'
print (new_string)
print (type(new_string))
Output: abcdef
<class 'str'>
#string*integrar
newest_string = "abc" *3
print (newest_string)
print (type(newest_string))
output: abcabcabc
<class 'str'>
Excercise:
# Define a float
y = 1.
print(y)
print(type(y))
# Convert float to integer with the int function
z = int(y)
print(z)
print(type(z))
Output: 1.0
<class 'float'>
1
<class 'int'>
def get_expected_cost(beds, baths, has_basement):
value = 80000+ 30000*beds +10000 * baths + 40000* has_basement
return value
def cost_of_project(engraving, solid_gold):
cost = solid_gold * (100 + 10 * len(engraving)) + (not solid_gold) * (50 + 7 * len(engraving))
return cost
def cost_of_project(engraving, solid_gold):
cost = solid_gold * (100 + 10 * len(engraving)) + (not solid_gold) * (50 + 7 * len(engraving))
return cost
project_one = cost_of_project("Charlie+Denver", True)
print(project_one)
project_two = cost_of_project("08/10/2000", False)
print(project_two)
Conditions and Conditional Statements
Conditions
In programming, conditions are statements that are either True or False
most common ways of writing conditions just compare two different values
print(2>3)
Output: False
var_one = 1
var_two = 2
print (var_one < 1)
print (var_two>= var_one)
Output: False
True
common symbols
Symbol Meaning
== equals
!= does not equal
< less than
<= less than or equal to
> greater than
>= greater than or equal to
Conditional statements
conditions to modify how your function runs
"if" statements
def evaluate_temp(temp):
#set an initaial message
message = "Normal Temparature"
# update value of message only if temparature is greater than 38
if temp > 38:
message= "Fever!"
return message
"if ... else" statements
False statement then use "else"
True statement then use "if"
def evaluate_temp_with_else(temp):
if temp > 38:
message = "Fever!"
else:
message = "Normal temperature."
return message
print(evaluate_temp_with_else(37))
Output: Normal temperature.
"if ... elif ... else" statements
elif = else if
def evaluate_temp_with_elif(temp):
if temp > 38:
message= "Fever!"
elif temp > 35:
message= "Normal"
else:
message = "low temparature"
return message
print (evaluate_temp_with_elif(36))
Output: Normal
Examples
def get_taxes(earnings):
if earnings < 12000:
tax_owed= .25 * earnings
if earnings > 12000:
tax_owed= .30 * earnings
return tax_owed
ana_taxes = get_taxes (9000)
bob_taxes = get_taxes (15000)
print (ana_taxes)
print(bob_taxes)
Output:
2250.0
4500.0
def add_three_or_eight(number):
if number < 10:
result = number + 3
if number > 10:
result = number + 8
return result
print(add_three_or_eight(7))
Output: 10
def add_three_or_eight(number):
if number < 10:
result = number + 3
if number > 10:
result = number + 8
return result
print(add_three_or_eight(11))
Output: 19
def get_dose(weight):
# Dosage is 1.25 ml for anyone under 5.2 kg
if weight < 5.2:
dose = 1.25
elif weight < 7.9:
dose = 2.5
elif weight < 10.4:
dose = 3.75
elif weight < 15.9:
dose = 5
elif weight < 21.2:
dose = 7.5
# Dosage is 10 ml for anyone 21.2 kg or over
else:
dose = 10
return dose
print (get_dose(12))
Output: 5
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