Traversing a String

# Traversing

name = "Welcome"

for ch in name:
  print(ch, '-', end = ' ')
  
  
# Reversing a string

## W - e - l - c - o - m - e -

name = "Reverse me"

# The Slice notation in python has the syntax -

# list[<start>:<stop>:<step>]
# So, when you do a[::-1], it starts from the end towards the first taking each element. So it reverses a. This is applicable for lists/tuples as well.

print(name[::-1])

## em esreveR

lgth = len(name)

for a in range(-1, (-lgth-1), -1):
  print(name[a])


## Split the string into a list of characters, reverse the list, then rejoin into a single string

## e
## m
##  
## e
## s
## r
## e
## v
## e
## R

print(''.join(reversed("Hello world")))

## dlrow olleH

Checking identities of two strings

You use == when comparing values and is when comparing identities.

lang           = ['Java','Python']

more_lang      = lang

print(lang == more_lang) # -> True

## True

print(lang is more_lang) # -> True

## True

even_more_lang = ['Java','Python']

print(lang == even_more_lang) #-> True

## True

print(lang is even_more_lang) #-> False

## False

print(id(lang))

## 842617096

print(id(more_lang))

## 842617096

print(id(even_more_lang))

## 865271048

Checking capital letters

The istitle() method checks if each word is capitalized.

print( 'The Hilman'.istitle() ) #=> True

## True

print( 'The Cat'.istitle() ) #=> False

## True

print( 'the rice'.istitle() ) #=> False

## False

Checking if string contains another

print( 'A' in 'The string containing A' ) #=> True

## True

print( 'Apple in' in 'The string containing A' ) #=> False

## False

Finding the index of a substring in a string

print('The'.find('The string containing A'))

## -1