how yo change letters to capital python code example

Example 1: capitalize string python

# Python string capitalization
string = "this isn't a #Standard Sntence."
string.capitalize() # "This isn't a #standard sentence."
string.upper() # "THIS ISN'T A #STANDARD SENTENCE."
string.lower() # "this isn't a #standard sentence."
string.title() # "This Isn'T A #Standard Sentence."

# ---------- Alternate Title Case ----------
# "This Isn't A #standard Sentence."

from string import capwords
string = capwords(string) # capitalize characters after each separator.
# see the doc: string.capwords(s, sep=None), separator defaults to space

# or implement it directly:
string = " ".join(s.capitalize() for s in string.split())
#

Example 2: converting capital letters to lowercase and viceversa in python

s=input()
new_str=""
for i in range (len(s)):
    if s[i].isupper():
        new_str+=s[i].lower()
    elif s[i].islower():
        new_str+=s[i].upper()
    else:
        new_str+=s[i]
print(new_str)