Learning Python -Day 4

DAY 4

n=int(input("Enter a number"))
i=1
while(i<=n):
    print(end=" ""hello")
    i+=1

run the function CTL+shift+fn+F10

Enter a number15

 hello hello hello hello hello hello hello hello hello hello hello hello hello hello hello

WHILE LOOP IS USED WHEN WE KNOW THE CONDITION, THE LOOP WILL LOOK INTO

Factorial example

n=int(input("Enter a number"))
i=n
f=1
while(i>=1):
    f=f*i
    i-=1
    print("fatorial of",n,"is",f)

run the function CTL+shift+fn+F10

Enter a number7

fatorial of 7 is 7

fatorial of 7 is 42

fatorial of 7 is 210

fatorial of 7 is 840

fatorial of 7 is 2520

fatorial of 7 is 5040

fatorial of 7 is 5040

Find Sum of digits example

n=int(input("Enter a number"))
s=0

while(n!=0):
    r=n%10
    n=n//10
    s=s+r
print("sum of digits ",s)

    print("not a palindrome")

run the function CTL+shift+fn+F10

Enter a number435

sum of digits  12

Reverse of a number

n=int(input("Enter a number"))
m=n
a=0

while(n!=0):
    r=n%10
    n=n//10
    a=a*10+r
print("Reverse number is ",a)
if(a==m):
    print("palindrom no")
else:
    print("not a palindrome")

run the function CTL+shift+fn+F10

Enter a number131

Reverse number is  131

palindrom no

STRING

str1="This is Python string"
print("String is",str1)

run the function CTL+shift+fn+F10

String is This is Python string

0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
T	H	i	s		I	s		P	Y	T	H	O	N		S	T	R	I	N	g

str1="This is Python string"

print("str1[2]",str1[2])

run the function CTL+shift+fn+F10

The output is I as string 2 is i

 also

Indexing¶









It is helpful to think of a string as an ordered sequence. Each element in the sequence can be accessed using an index represented by the array of numbers:  



















 The first index can be accessed as follows:

Because indexing starts at 0, it means the first index is on the index 0. 

To find length of the string

str1="This is Python string"

print("Length of string is",len(str1))

run the function CTL+shift+fn+F10

Length of string is 21

str1="This is Python string"

print(str1.index("i"))

run the function CTL+shift+fn+F10

2

str1="This is Python string"

print(str1[3:11])

run the function CTL+shift+fn+F10

s is Pyt

It will end on 10 instead of 11 as its value is n-1

str1="This is Python string"

print(str1[2:15:2])

run the function CTL+shift+fn+F10

i sPto

Here in the above code, [2:15:2]), first 2 is the start, 15 is the end and 2 is the step or gap of

program for the reverse string print

str1="This is Python string"

print(str1[::-1])

run the function CTL+shift+fn+F10

gnirts nohtyP si sihT

If you need to find index within range

str1="This is Python string"

print(str1.index("i",3,10))

run the function CTL+shift+fn+F10

5

To count no. of times the letter repeats itself in the string

str1="This is Python string"

print("Count number of i in string",str1.count("i"))

run the function CTL+shift+fn+F10

Count number of i in string 3

To convert string in upper case

str1="This is Python string"

print("String in upper case is ",str1.upper())

run the function CTL+shift+fn+F10

String in upper case is  THIS IS PYTHON STRING

To convert string in lower case

str1="This is Python string"

print("String in lower case is ",str1.lower())

run the function CTL+shift+fn+F10

String in lower case is  this is python string

To make first letter as Capital

str1="This is Python string"

print("String capitalize ",str1.capitalize())

run the function CTL+shift+fn+F10

String capitalize  This is python string

To make first letter of every word capital

str1="This is Python string"

print("String in title case is ",str1.title())

run the function CTL+shift+fn+F10

String in title case is  This Is Python String

To check if string is in upper case, lower case or title or alphabets are contained in string only or alphanumeric string

print("Srting in upper case??",str1.isupper())
print("Srting in lower case??",str1.islower())
print("Srting in title case??",str1.istitle())

print(str1.isalpha())

print(str1.isalnum())



str1="This is Python string"

print(str1.startswith("Thi"))

run the function CTL+shift+fn+F10

True

These all are check commands

print(str1.startswith("thi"))

print(str1.endswith("ython"))

print(str1.endswith("tring"))





s1='Ptyhon'

for i in s1:

    print(i)





print(s1*3)

print(s1+"Hello")



s1='Ptyhon'

print(s1.center(10))

run the function CTL+shift+fn+F10

  Ptyhon  

s1='Ptyhon'

print(s1.center(10,"$"))

run the function CTL+shift+fn+F10

$$Ptyhon$$

To print from left

print(s1.ljust(10))

To print from left and fill the spaces

s1='Ptyhon'

print(s1.ljust(10,'*'))

run the function CTL+shift+fn+F10

Ptyhon****

To print from right

s1='Ptyhon'

print(s1.rjust(10,'#'))

run the function CTL+shift+fn+F10

####Ptyhon

To find index from the right

str1="This is Python string"

print(str1.rfind("i"))

run the function CTL+shift+fn+F10

18

Learning Python- Day 5