Strings and their... processing

topic = "Foundations of DataScience"
print(topic)

Foundations of DataScience

print(topic[0])
# prints the very first character...

F

print(topic[10])

s

print(topic[-1])
# prints the last character in the given string

e

print(topic[0:10])
# take everything from 0 to 10th character (inclusive of 0th character and excluding 10th character)

Foundation

print(topic[12:16])

of D

print(topic.lower())

foundations of datascience

print(topic.upper())
# here the actual variable topic is not converted to lower case but it is converted and displayed in lower case

FOUNDATIONS OF DATASCIENCE

# to make the string variable into lower case then 
topic = topic.lower()
print (topic)

foundations of datascience

topic = topic.upper()
print(topic)

FOUNDATIONS OF DATASCIENCE

topic.islower()  #returns either True or False, if the data in the variable is lower case

False

topic.isupper()

True

topic.isalnum()

False

print(topic.isupper())

True

print(topic)

FOUNDATIONS OF DATASCIENCE

print(topic.find("DATA"))

15

print(topic[15])

D

print(topic.replace('DATA', 'DDAATTAA '))

FOUNDATIONS OF DDAATTAA SCIENCE

golden_ratio = 55/34

print(type(golden_ratio))

<class 'float'>

print(golden_ratio.is_integer())

False

print(golden_ratio.as_integer_ratio())

(3642617345667313, 2251799813685248)

print(3642617345667313/2251799813685248)

1.6176470588235294

print(golden_ratio)

1.6176470588235294

print(55//34, 55/34)

1 1.6176470588235294

# to get remainder
print(55 % 34)

21

print("exponentation: 2 ** 3 = ", 2**3)

exponentation: 2 ** 3 =  8

If, For, While blocks

https://www.repath.in/Conditional-IF-Statement/

hours_per_week = 10
my_name = "Arundhati"

if hours_per_week >= 10:
    print (my_name + "'s working hours are greater than 10hrs, doing well")

Arundhati's working hours are greater than 10hrs, doing well

if hours_per_week > 10:
    print("you are doing well")
else:
    print("You need to do more hours")

You need to do more hours

https://www.repath.in/Interative-Structures/

# printing Fibonacci series with loops
i = 1
j = 1
print(i)
print(j)
for k in range(20):
    temp = i + j
    i = j
    j = temp
    print(k, temp)

1
1
0 2
1 3
2 5
3 8
4 13
5 21
6 34
7 55
8 89
9 144
10 233
11 377
12 610
13 987
14 1597
15 2584
16 4181
17 6765
18 10946
19 17711

i = 1
j = 1
print(i)
print(j)
while j < 100:
    temp = i + j
    i =  j
    j = temp
    print(temp)

1
1
2
3
5
8
13
21
34
55
89
144

https://www.repath.in/Procedures-and-Functions/

def fibonacci(pos):
    a = 1
    b = 1
    for i in range(pos):
        temp = a + b
        b = a
        a = temp
    return temp

# instead of printing the entire output, we can also print only the outcome of the target number
fibonacci(5)

13

fibonacci(3)

5

print(fibonacci(2), fibonacci(4))

3 8

print(fibonacci(7), fibonacci(8))

34 55

# the initial values need not be 1 always, but can be desired sequence for a and b
def fibo_relative(pos, a, b):
    print(a)
    print(b)
    for i in range(pos):
        temp = a + b
        a = b
        b = temp
        print(temp)
    return(temp)

print(fibo_relative(10,3,2))

3
2
5
7
12
19
31
50
81
131
212
343
343

# the series starts from the given initial values for a and b 
# in the following example, a = 34 as initial value, instead of 1 and
# b has the value of 55,
# so the loop runs with initial values of 34 and 55 for 3 iterations
print(fibo_relative(3, 34, 55))

34
55
89
144
233
233

# writing the same function with initial values in the funtion definition itself
# in this example, the initial values are optional - meaning
# if the initial values are not given, 1 is taken for a and b, if given, the given values are considered
def fibo_overload(pos, a=1, b=1):
    for i in range(pos):
        temp = a + b
        a = b
        b = temp
        print(temp)
    return temp

print(fibo_overload(10))

2
3
5
8
13
21
34
55
89
144
144

print(fibo_overload(5, 5, 5))

10
15
25
40
65
65

recursive function

def fibo_recursive(n, a = 1, b = 1):
    if n > 1:
        return fibo_recursive(n - 1, b, a + b)
    else:
        return a + b

print(fibo_recursive(10))

144