1. String.py

# strings are immutable in python

name = "Asad"

# format string to user variables
s = f"HELLO {name}"


s.upper()
s.lower()
s.swapcase()
# capitalize first letter
s.capitalize()
# capitalize every word
s = s.title()

# -------------------

# remove whitespace
s.strip()
# from individual sides
s.lstrip()
s.rstrip()

# -------------------

# Replace String
s.replace("H", "J")

# return comma separated list
s.split(',')

# Slicing
s[2:5]
# from start
s[:5]
# to end
s[2:]
# Negative Indexing
s[-5:-2]

# return index of searched letter
print(s.index("R"))

# ------------------

# Format String
txt = "My name is John, and I am {}"
print(txt.format(36))

# Formatting Types
# https://www.w3schools.com/python/ref_string_format.asp
txt = "My name is John, and I am {:.2f}"

# Index Numbers
myorder = "I want to pay {2} dollars for {0} pieces of item {1}."
print(myorder.format(25, 30, 35))

# Named Indexes
myorder = "I have a {carname}, it is a {model}."
print(myorder.format(carname = "Ford", model = "Mustang"))


# multiline string
a = """Lorem ipsum dolor sit amet,
consectetur adipiscing elit,
sed do eiusmod tempor incididunt
ut labore et dolore magna aliqua."""

# Check String
# if a certain phrase or character is present in a string with 'in'
txt = "The best things in life are free!"
if "free" in txt:
    print("ok")