20. Bytes
Syntax:
- bytes_var = bytes(x, encoding, error)
Returns a bytes object. It can create empty bytes object of the specified size or convert objects into bytes objects.
- Parameters:
x – If x is an integer, an empty bytes object of the specified size will be created.
x – If x is a String, the encoding is required.
x – If x is an iterable, such as a list, it must be of integers from 0 to 255.
encoding – The encoding of the string such as ‘utf-8’
error – Specifies what to do if the encoding fails.
x = bytes(4)
print(x)
# Output is b'\x00\x00\x00\x00'
x = bytes("abc123", "utf-8")
print(x)
# Output is b'abc123'
num_list = [1, 2, 3, 4, 5]
num_list_bytes = bytes(num_list)
print(num_list_bytes)
# Output is b'\x01\x02\x03\x04\x05'
num_list = range(256)
num_list_bytes = bytes(num_list)
print(num_list_bytes)
'''Output is
b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\x7f\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff'
'''
20.1. bytes Methods
The bytes type in Python provides a variety of methods for interacting with and manipulating byte data. Below are some commonly used methods:
20.2. count
- count(sub[, start[, end]])
Return the number of non-overlapping occurrences of the substring sub.
Example:
my_bytes = b"Hello, World!" count = my_bytes.count(b'o') print(count) # Output: 2
20.3. find
- find(sub[, start[, end]])
Return the lowest index where the substring sub is found.
Example:
my_bytes = b"Hello, World!" index = my_bytes.find(b'World') print(index) # Output: 7
20.4. index
- index(sub[, start[, end]])
Like find(), but raises a ValueError if the substring is not found.
Example:
my_bytes = b"Hello, World!" index = my_bytes.index(b'World') print(index) # Output: 7
20.5. split
- split(sep=None, maxsplit=-1)
Split the bytes object into a list of byte objects, using sep as the delimiter.
Example:
my_bytes = b"Hello, World!" parts = my_bytes.split(b', ') print(parts) # Output: [b'Hello', b'World!']
20.6. join
- join(iterable)
Concatenate any number of bytes objects, with the bytes object acting as a separator.
Example:
parts = [b'Hello', b'World!'] joined = b', '.join(parts) print(joined) # Output: b'Hello, World!'
20.7. replace
- replace(old, new[, count])
Return a copy of the bytes object with all occurrences of the substring old replaced by new.
Example:
my_bytes = b"Hello, World!" replaced = my_bytes.replace(b'World', b'Python') print(replaced) # Output: b'Hello, Python!'
20.8. strip
- strip([chars])
Return a copy of the bytes object with leading and trailing whitespace removed.
Example:
my_bytes = b" Hello, World! " stripped = my_bytes.strip() print(stripped) # Output: b'Hello, World!'
20.9. startswith
- startswith(prefix[, start[, end]])
Return True if the bytes object starts with the specified prefix.
Example:
my_bytes = b"Hello, World!" result = my_bytes.startswith(b'Hello') print(result) # Output: True
20.10. endswith
- endswith(suffix[, start[, end]])
Return True if the bytes object ends with the specified suffix.
Example:
my_bytes = b"Hello, World!" result = my_bytes.endswith(b'World!') print(result) # Output: True
20.11. decode
- decode(encoding='utf-8', errors='strict')
Decode the bytes object to a string using the specified encoding.
Example:
my_bytes = b"Hello, World!" string = my_bytes.decode('utf-8') print(string) # Output: Hello, World!