Tutorial #3: Python Statements List – A+ Easy

Python Statements List Like Professional!

Complete Python Bootcamp From Zero to Hero in Python (Statements, Loop)

How to Write a Python Statements List?

Python VS Other Languages

Other Languages
if (a>b){
    a = 2;
    b = 4;
}
Python
if a>b:
    a = 2
    b = 4

Python Identification

Other Languages
if (x)
    if(y)
        code-statement;
else
    another-code-statement;
Python
if x:
    if y:
        code-statement
else:
    another-code-statement

How to Use Python Statements List?

Python “if, else”

Multiple Branches

Python Statements List Loop

for loop number list

for loop if else statement

for loop sums

for loop string letter

for loop tuple

for loop list tuples

for loop key, values and items

Python “while loop”

break: Breaks out of the current closest enclosing loop.
continue: Goes to the top of the closest enclosing loop.
pass: Does nothing at all.

The general format of a while loop is:
while test:
    code statements
else:
    final code statements

See and download here

Python “break, continue, pass”

The three statements are defined by:
while test: 
    code statement
    if test: 
        break
    if test: 
        continue 
else:

See and download here

It is possible to create an infinitely running loop with while statements. For example:

# WARNING: DO NOT RUN THIS CODE!!!!
while True:
    print("I'm stuck in an infinite loop!")

Using “pass” in loops to avoid syntax error

range

enumerate with tuple unpaking

list enumerate, zip, list zip, for zip format

Python “in” operator

Python “min and max”

Python random, import, shuffle, randint

Get specific letter in string

Square numbers in range and turn into list

Check even numbers in a range

Convert Celsius to Fahrenheit

Contents

1. Introduction

1.1 Python VS Other Languages

1.2 Indentation

2. if, elif, else Statements

2.1 Example if, else

2.2 Multiple Branches

3. For Loops

3.1 Loop number list

3.2 Loop if else statement

3.3 Loop sums

3.4 Loop string letter

3.5 Loop tuple

3.6 Loop List Tuples

3.7 Loop key, values and items

4. While Loops

4.1 While loop

4.2 Using break, continue, pass

4.3 Using Pass in loops to avoid syntax error

5. Useful Operators

5.1 Range

5.2 Enumerate

5.3 Zip

5.4 in operator

5.5 min and max

5.6 random

6. List Comprehensions

6.1 Grab every letter in string

6.2 Square numbers in range and turn into list

6.3 Check even numbers in a range

6.4 Convert Celsius to Fahrenheit

1.1 Python VS Other Languages

Other Languages

if (a>b){

a = 2;

b = 4;

}

—————————————————————–

Python

if a>b:

a = 2

b = 4

—————————————————————–

1.2 Indentation

Other Languages

if (x)

if(y)

code-statement;

else

another-code-statement;

—————————————————————–

Python:

if x:

if y:

code-statement

else:

another-code-statement

—————————————————————–

2.1 Example if, else

if True:

print(‘It was true!’)

# output: It was true!

—————————————————————–

x = False

if x:

print(‘x was True!’)

else:

print(‘I will be printed in any case where x is not true’)

# output: I will be printed in any case where x is not true

—————————————————————–

2.2 Multiple Branches

if 3 > 2:

print(‘TRUE!’)

# output: TRUE!

—————————————————————–

hungry = True

if hungry:

print(‘HUNGRY!’)

else:

print(‘NOT HUNGRY!’)

# output: HUNGRY!

—————————————————————–

loc = ‘Bank’

if loc == ‘Auto Shop’:

print(‘Welcome to the Auto Shop!’)

elif loc == ‘Bank’:

print(‘Welcome to the bank!’)

elif loc == ‘Store’:

print(‘Welcome to the store!’)

else:

print(‘Where are you?’)

# output: Welcome to the bank!

—————————————————————–

person = ‘Al Ardosa’

if person == ‘Al Ardosa’:

print(‘Welcome Al Ardosa!’)

else:

print(“Welcome, what’s your name?”)

# output: Welcome Al Ardosa!

—————————————————————–

person = ‘Al Ardosa’

if person == ‘Sammy’:

print(‘Welcome Sammy!’)

elif person == ‘Al Ardosa’:

print(‘Welcome Al Ardosa!’)

else:

print(“Welcome, what’s your name?”)

# output: Welcome Al Ardosa!

—————————————————————–

3.1 For loop number list

mylist = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

for mynum in mylist:

print(mynum)

# output:

1

2

3

4

5

6

7

8

9

10

—————————————————————–

3.2 For loop if else statement

# print only the even numbers from that list!

# % is modulo to get the remainder only

mylist = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

for mynum in mylist:

if mynum % 2 == 0:

print(‘Even Number’, mynum)

else:

print(f’Odd number: {mynum}’)

# output:

Odd number: 1

Even Number 2

Odd number: 3

Even Number 4

Odd number: 5

Even Number 6

Odd number: 7

Even Number 8

Odd number: 9

Even Number 10

—————————————————————–

3.3 For loop sums

mylist = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

# Start sum at zero

mysum = 0

for mynum in mylist:

mysum = mysum + mynum

print(mysum)

# output: 55

—————————————————————–

mylist = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

# Start sum at zero

mysum = 0

for mynum in mylist:

# you can also use +=

mysum += mynum

print(mysum)

# output: 55

—————————————————————–

3.4 For loop string letter

for myletter in ‘This is a string.’:

print(myletter)

# output:

T

h

i

s

i

s

a

s

t

r

i

n

g

.

—————————————————————–

for _ in ‘Hey!’:

print(‘Cool!’)

# output:

Cool!

Cool!

Cool!

Cool!

—————————————————————–

3.5 For loop tuple

tups = (1, 2, 3, 4, 5)

for t in tups:

print(t)

# output:

1

2

3

4

5

—————————————————————–

3.6 For loop list tuples

mylist = [(2, 4), (6, 8), (10, 12)]

for tups in mylist:

print(tups)

# output:

(2, 4)

(6, 8)

(10, 12)

—————————————————————–

mylist = [(2, 4), (6, 8), (10, 12)]

# Now with unpacking!

for (t1, t2) in mylist:

print(t1)

# output:

2

6

10

—————————————————————–

3.7 For loop key, values and items

d = {‘k1’: 1, ‘k2’: 2, ‘k3’: 3}

for item in d:

print(item)

print(‘—————–‘)

print(d.items())

print(‘—————–‘)

# Dictionary unpacking

for key, value in d.items():

print(key)

print(value)

print(‘—————–‘)

print(list(d.keys()))

print(‘—————–‘)

print(sorted(d.values()))

# output:

k1

k2

k3

—————–

dict_items([(‘k1’, 1), (‘k2’, 2), (‘k3’, 3)])

—————–

k1

1

k2

2

k3

3

—————–

[‘k1’, ‘k2’, ‘k3’]

—————–

[1, 2, 3]

—————————————————————–

4.1 While loop

break: Breaks out of the current closest enclosing loop.

continue: Goes to the top of the closest enclosing loop.

pass: Does nothing at all.

—————————————————————–

The general format of a while loop is:

while test:

code statements

else:

final code statements

—————————————————————–

x = 0

while x < 5:

print(‘x is currently: ‘, x)

print(‘ x is still less than 5, adding 1 to x’)

x += 1

else:

print(‘All Done!’)

#output:

x is currently: 0

x is still less than 5, adding 1 to x

x is currently: 1

x is still less than 5, adding 1 to x

x is currently: 2

x is still less than 5, adding 1 to x

x is currently: 3

x is still less than 5, adding 1 to x

x is currently: 4

x is still less than 5, adding 1 to x

All Done!

—————————————————————–

4.2 using break, continue, pass

The three statements are defined by:

while test:

code statement

if test:

break

if test:

continue

else:

—————————————————————–

x = 0

while x < 5:

print(f’x is currently: {x}’)

print(‘ x is still less than 5, adding 1 to x’)

x += 1

if x == 3:

print(‘x==3’)

else:

print(‘continuing…’)

continue

# output:

x is currently: 0

x is still less than 5, adding 1 to x

continuing…

x is currently: 1

x is still less than 5, adding 1 to x

continuing…

x is currently: 2

x is still less than 5, adding 1 to x

x==3

x is currently: 3

x is still less than 5, adding 1 to x

continuing…

x is currently: 4

x is still less than 5, adding 1 to x

continuing…

—————————————————————–

# put in a break once x ==3 and see if the result makes sense:

x = 0

while x < 10:

print(f’x is currently: {x}’)

print(‘ x is still less than 10, adding 1 to x’)

x += 1

if x == 3:

print(‘Breaking because x==3’)

break

else:

print(‘continuing…’)

continue

# output:

x is currently: 0

x is still less than 10, adding 1 to x

continuing…

x is currently: 1

x is still less than 10, adding 1 to x

continuing…

x is currently: 2

x is still less than 10, adding 1 to x

Breaking because x==3

—————————————————————–

It is possible to create an infinitely running loop with while statements. For example:

# DO NOT RUN THIS CODE!!!!

while True:

print(“I’m stuck in an infinite loop!”)

—————————————————————–

4.3 Using Pass in loops to avoid syntax error

x = [1, 2, 3]

for item in x:

# my comment

pass

print(‘end of script’)

—————————————————————–

5.1 Range

print(range(0,11))

#output: range(0,11)

# 11 is not included, up to but not including 11

print(list(range(0,11)))

#output: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

—————————————————————–

# Third parameter is step size!

# step size just means how big of a jump/leap/step you

# take from the starting number to get to the next number.

print(list(range(0,11,2)))

# output: [0, 2, 4, 6, 8, 10]

—————————————————————–

print(list(range(0,101,10)))

#output: [0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100]

—————————————————————–

5.2 Enumerate

index_count = 0

for letter in ‘abcde’:

print(“At index {} the letter is {}”.format(index_count,letter))

index_count += 1

#output:

At index 0 the letter is a

At index 1 the letter is b

At index 2 the letter is c

At index 3 the letter is d

At index 4 the letter is e

—————————————————————–

# tuple unpacking!

for i,letter in enumerate(‘abcde’):

print(“At index {} the letter is {}”.format(i,letter))

#output:

At index 0 the letter is a

At index 1 the letter is b

At index 2 the letter is c

At index 3 the letter is d

At index 4 the letter is e

—————————————————————–

5.3 zip

print(list(enumerate(‘abcde’)))

#output:

[(0, ‘a’), (1, ‘b’), (2, ‘c’), (3, ‘d’), (4, ‘e’)]

—————————————————————–

mylist1 = [1, 2, 3, 4, 5]

mylist2 = [‘a’, ‘b’, ‘c’, ‘d’, ‘e’]

print(zip(mylist1, mylist2))

#output:

<zip object at 0x0000000002821D08>

—————————————————————–

print(list(zip(mylist1,mylist2)))

#output:

[(1, ‘a’), (2, ‘b’), (3, ‘c’), (4, ‘d’), (5, ‘e’)]

—————————————————————–

for item1, item2 in zip(mylist1, mylist2):

print(‘For this tuple, first item was {} and second item was {}’.format(item1, item2))

#output:

For this tuple, first item was 1 and second item was a

For this tuple, first item was 2 and second item was b

For this tuple, first item was 3 and second item was c

For this tuple, first item was 4 and second item was d

For this tuple, first item was 5 and second item was e

—————————————————————–

5.4 in operator

print(‘x’ in [‘x’, ‘y’, ‘z’])

#output: True

—————————————————————–

print(‘w’ in [‘x’, ‘y’, ‘z’])

#output: False

—————————————————————–

5.5 min and max

mylist = [10, 20, 30, 40, 100]

print(min(mylist))

# output: 10

—————————————————————–

print(max((mylist)))

# output: 100

—————————————————————–

5.6 random

mylist = [10, 20, 30, 40, 100]

from random import shuffle

shuffle(mylist)

print(mylist)

#output: [40, 20, 10, 30, 100]

—————————————————————–

from random import randint

print(randint(0, 100))

#output: 88

—————————————————————–

6.1 Grab every letter in string

lc = [x for x in ‘word’]

print(lc)

#output: [‘w’, ‘o’, ‘r’, ‘d’]

—————————————————————–

6.2 Square numbers in range and turn into list

lc = [x ** 2 for x in range(0, 11)]

print(lc)

# output: [0, 1, 4, 9, 16, 25, 36, 49, 64, 81, 100]

—————————————————————–

6.3 Check even numbers in a range

lc = [x for x in range(11) if x % 2 == 0]

print(lc)

# output: [0, 2, 4, 6, 8, 10]

or

lc = [x if x % 2 == 0 else ‘ODD’ for x in range(0, 11)]

print(lc)

# output: [0, ‘ODD’, 2, ‘ODD’, 4, ‘ODD’, 6, ‘ODD’, 8, ‘ODD’, 10]

—————————————————————–

6.4 Convert Celsius to Fahrenheit

celsius = [0, 10, 20.1, 34.5]

fahrenheit = [((9 / 5) * temp + 32) for temp in celsius]

print(fahrenheit)

# output: [32.0, 50.0, 68.18, 94.1]

—————————————————————–

lc = [x ** 2 for x in [x ** 2 for x in range(11)]]

print(lc)

# output: [0, 1, 16, 81, 256, 625, 1296, 2401, 4096, 6561, 10000]

Python Statements List
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