upper, lower & casefold in Python

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*Memo for string, bytes and bytearray functions:

• My post explains swapcase(), title() and capitalize().
• My post explains isupper(), islower() and istitle().
• My post explains encode() and decode().

*Memo for a string, bytes and bytearray:

• My post explains a string.
• My post explains a bytes.
• My post explains a bytearray.

str.upper() and bytes.upper() or bytearray.upper() can make the string and bytes or bytearray uppercase respectively for very caseless matching as shown below:

*Memo:

• Each has no arguments.
• The German Alphabet ẞ(ß) is used after a long vowel or dipthong, like in Straße or beißen.
• The German Alphabets SS(ss) are used after a short vowel sound, like in Fluss or Kuss.

<String>:

v = 'hElLo WoRlD'

print(v.upper())
# HELLO WORLD

v = 'ß' # Lowercase German Alphabet

print(v.upper())
# SS

v = 'ẞ' # Uppercase German Alphabet

print(v.upper())
# ẞ # Uppercase German Alphabet

<Bytes & Bytearray>:

v1 = b'hElLo WoRlD'
v2 = bytearray(b'hElLo WoRlD')

print(v1.upper())
# b'HELLO WORLD'

print(v2.upper())
# bytearray(b'HELLO WORLD')

# Lowercase German Alphabet
v1 = 'ß'.encode()
v1 = b'\xc3\x9f'
v2 = bytearray(b'\xc3\x9f')

print(v1.upper())
# b'\xc3\x9f'

print(v2.upper())
# bytearray(b'\xc3\x9f')

# Uppercase German Alphabet
v1 = 'ẞ'.encode()
v1 = b'\xe1\xba\x9e'
v2 = bytearray(b'\xe1\xba\x9e')

print(v1.upper())
# b'\xe1\xba\x9e'

print(v2.upper())
# bytearray(b'\xe1\xba\x9e')

str.lower() and bytes.lower() or bytearray.lower() can make the string and bytes or bytearray lowercase respectively for normal caseless matching as shown below:

*Memo:

• Each has no arguments.

<String>:

v = 'hElLo WoRlD'

print(v.lower())
# hello world

v = 'ß' # Lowercase German Alphabet

print(v.lower())
# ß # Lowercase German Alphabet

v = 'ẞ' # Uppercase German Alphabet

print(v.lower())
# ß # Lowercase German Alphabet

<Bytes & Bytearray>:

v1 = b'hElLo WoRlD'
v2 = bytearray(b'hElLo WoRlD')

print(v1.lower())
# b'hello world'

print(v2.lower())
# bytearray(b'hello world')

# Lowercase German Alphabet
v1 = 'ß'.encode()
v1 = b'\xc3\x9f'
v2 = bytearray(b'\xc3\x9f')

print(v1.lower())
# b'\xc3\x9f'

print(v2.lower())
# bytearray(b'\xc3\x9f')

# Uppercase German Alphabet
v1 = 'ẞ'.encode()
v1 = b'\xe1\xba\x9e'
v2 = bytearray(b'\xe1\xba\x9e')

print(v1.lower())
# b'\xe1\xba\x9e'

print(v2.lower())
# bytearray(b'\xe1\xba\x9e')

str.casefold() can make the string lowercase for very caseless matching as shown below:

*Memo:

• It has no arguments.
• bytes.casefold() and bytearray.lower() don't exist for a bytes and bytearray respectively.

<String>:

v = 'hElLo WoRlD'

print(v.casefold())
# hello world

v = 'ß' # Lowercase German Alphabet

print(v.casefold())
# ss

v = 'ẞ' # Uppercase German Alphabet

print(v.casefold())
# ss