In Python, a string is a sequence of characters that can be manipulated using various functions and methods.

Some of the main ways to manipulate strings:

Slicing:

Extracting a substring from a larger string by specifying a range of indices.

Basic syntax is : str[start:end:step]

  string = "Hello"
  string[1:4]  # "ell"
  #starting from position 1 to 
  string[:4]   # "Hell"
  string[2:]   # "llo" 
  string[:]    # "Hello"

  '''You can use negative indices to slice from the end, and specify 
  a step to slice with a stride'''

  string = "Hello"
  string[-4:-1] # "ell"
  string[::-1]  # "olleH"
  string[::2]   # "Hlo"

String methods:

Useful functions to manipulate strings(lower(),upper(), split(), join(), replace(), find() )

string = 'Learn Python'
string.lower()  # returns 'learn python'
string.upper()  # returns 'LEARN PYTHON'

#string to list
string = 'Learn Python Programming'
print(string.split(' ')) # output =  ['Learn', 'Python', 'Programming']

#list to string
parts = ['Learn', 'Python', 'Programming']
string.join(parts) # output = 'Learn Python Programming'

string = 'Learn Python Programming'
string.replace('Python', 'Java') # output = 'Learn Java Programming'

string = 'Bitsnotion'.find('s')
print(abc)# output = 3

String formatting:

Integrate variables into strings.

Python offers various methods for string formatting:

The f-strings (available in Python 3.6+)
The str.format() method
The % operator (deprecated in Python 3)

name = "Nirmal"
age = 23

print(f"Hello, my name is {name} and I'm {age} years old.")
print("Hello, my name is {} and I'm {} years old.".format(name, age))

# Both output =  "Hello, my name is Nirmal and I'm 23 years old."

Foat formatting options :

To use these options, build your expression within braces as follows:

The float variable is what’s being formatted
A colon (:) separates what’s being formatted from the syntax used to format it
. number indicates the desired precision
A letter indicates the presentation type

num = 1234.987123
print(f'{num:.2f}')#Output = 1234.99

Some others mostly used presentation types:

Type	Meaning
'e'	Scientific notation. For a given precision p, formats the number in scientific notation with the letter ‘e’ separating the coefficient from the exponent. The coefficient has one digit before and p digits after the decimal point, for a total of p + 1 significant digits. With no precision given, e uses a precision of 6 digits after the decimal point for float, and shows all coefficient digits for decimal.
'f'	Fixed-point notation. For a given precision p, formats the number as a decimal number with exactly p digits following the decimal point.
'%'	Percentage. Multiplies the number by 100 and displays in fixed ('f') format, followed by a percent sign.

num = 1000.987123
print(f'{num:.3e}')#Output = 1.001e+03

decimal = 0.2497856
print(f'{decimal:.4%}') #Output = 24.9786%

String concatenation:

Combine multiple strings using the + operator or .join() method.

string1 = "Hello"  
string2 = "World!"

#method -1
print(string1 + string2) ## output = Hello World!
#method-2
string1 += string2
print(string1)  # output = Hello World!
#method-3
print("".join([string1, string2])) # HelloWorld!

String Data Types In Details