Learning Python-Basic course: Day 22, String Methods part-1

#Interpreting the string as an array of characters.
txt= "Python"
print(txt)
print("Length of the txt = ", len(txt))

#display string using in keyword
for ch in txt:
    print(ch)


#display the string in original form using range()
for ch in range(0, len(txt)):
    print(txt[ch], end=" ")

print()
#to display in reverse order
for ch in range(len(txt)-1, -1 , -1):
    print(txt[ch], end="")

#We cannot append a character or pop using the standered length functions.
txt.append("a")
print(txt)

Python
Length of the txt =  6
P
y
t
h
o
n
P y t h o n 
nohtyPTraceback (most recent call last):
  File "C:/Users/aatma/Downloads/Example 1 .py", line 21, in <module>
    txt.append("a")
AttributeError: 'str' object has no attribute 'append'

#2. Upper case the first letter in this sentence:
txt = "hello, AND Welcome"
x = txt.capitalize()
print (x)
#output : Hello, and welcome

#3. Make the string lower case:
txt = "Hello, And Welcome!@#$"
x = txt.lower()
print (x)
#output : hello, and welcome

#4. Make the string upper case:
txt = "Hello, And Welcome"
x = txt.upper()
print (x)
#output : HELLO, AND WELCOME

Hello, and welcome
hello, and welcome!@#$
HELLO, AND WELCOME

#1.Print the word "computer", taking up the space of 25 characters,
#with "computer" in the middle:
txt = "computer"
x = txt.center(25)  

print ("hello",x,"world")
# 2 default spaces+25 total characters. so distance between hello and world must be 27 characters.

#2. Return the number of times the value "act" appears in the string:
txt = "I love programming, programming is my favorite activity"
print(txt)
x = txt.count('i') 

print ("Frequency of the value =" , x)
#case matters. Capital I and small i are treated differently.

#3. Check if the string ends with a punctuation sign .
txt = "Hello, welcome to my world."
x = txt.endswith("my world.")
print(x)


#4. Set the tab size to 5 whitespaces:
print("First\tsecond")
txt1 = "ACADEMY"              

txt = "A\tC\tA\tDE\tM Y" # backslah t (i.e. \t) represents tab space. 
x =  txt.expandtabs(6) #expands the tab spaces
print(x)


#5. Locates the word "welcome" in the string and returns the index:
txt = "Hello, welcome to my world."
print(txt)
x = txt.find("welcome")
print(x)
#output : 7
#if the result is -1, string does not exist in the sentence

hello          computer         world
I love programming, programming is my favorite activity
Frequency of the value = 6
True
First   second
A     C     A     DE    M Y
Hello, welcome to my world.
7

Please enter a string: a QUick Brown FOX jumps OVer the Lazy doG
A quick brown fox jumps over the lazy dog.

Please enter a string: Python
P 
P y 
P y t 
P y t h 
P y t h o 
P y t h o n