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Super Kai (Kazuya Ito)
Super Kai (Kazuya Ito)

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String in Python (2)

#python #string #str #function

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*Memos:

str() can create a string with or without many kinds of objects or can decode a bytes-like object as shown below:

*Memos:

  • The 1st argument is object(Optional-Default:'' or b''): *Memos:
    • If encoding and/or errors are/is set, it must be a bytes-like object to decode it and its default value is b'', working as decode().
    • b"", B'' or B"" can be used.
  • The 2nd argument is encoding(Optional-Default:'utf-8'): *Memos:
    • 'utf-8', 'utf-7', 'utf-16', 'big5', 'ascii', etc can be set to it.
    • You can see Standard Encodings for more possible values.
  • The 3rd argument is errors(Optional-Default:'strict'): *Memos:
    • It controls decoding error with the error handlers, 'strict', 'ignore', 'replace', 'xmlcharrefreplace', 'backslashreplace', etc.
    • 'strict' raises UnicodeError if the character, which cannot be decoded, exists.
    • 'ignore' ignores the character which cannot be decoded.
    • 'replace' replaces the character, which cannot be decoded, with �.
    • 'xmlcharrefreplace' replaces the character, which cannot be decoded, with a XML character e.g. ё.
    • 'backslashreplace' replaces the character, which cannot be decoded, with \uxxxx e.g. \u0451.
    • You can see more error handlers.
    • You can create your own error handler with codecs.register_error(). 
v = str() # Empty string v = str('12') # String v = str(12) # Integer v = str(1.2) # Floating-point number v = str(1.2+3.4j) # Complex number v = str([1, 2, 3]) # List v = str((1, 2, 3)) # Tuple v = str({1, 2, 3}) # Set v = str({'name':'John'}) # Dictionary v = str(iter([1, 2, 3])) # Iterator v = str(lambda: 10) # Function # No errors
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v = str() # Empty string  print(v) # Nothing
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v = str(object='12') # String  print(v, v[0], v[1]) # 12 1 2
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v = str(object=12) # Integer  print(v, v[0], v[1]) # 12 1 2
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v = str(object=1.2) # Floating-point number  print(v, v[0], v[1], v[2]) # 1.2 1 . 2
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v = str(object=1.2+3.4j) # Complex number  print(v, v[0], v[1], v[2], v[3], v[4], v[5], v[6], v[7], v[8], v[9]) # (1.2+3.4j) ( 1 . 2 + 3 . 4 j )
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v = str(object=[1, 2, 3]) # List  print(v, v[0], v[1], v[2], v[3], v[4], v[5], v[6], v[7], v[8]) # [1, 2, 3] [ 1 , 2 , 3 ]
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v = str(object=(1, 2, 3)) # Tuple  print(v, v[0], v[1], v[2], v[3], v[4], v[5], v[6], v[7], v[8]) # (1, 2, 3) ( 1 , 2 , 3 )
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v = str(object={1, 2, 3}) # Set  print(v, v[0], v[1], v[2], v[3], v[4], v[5], v[6], v[7], v[8]) # {1, 2, 3} { 1 , 2 , 3 }
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v = str(object={'name':'John'}) # Dictionary  print(v, v[0], v[1], v[2], v[3], v[4], v[5], v[6], v[7], v[8], v[9]) # {'name': 'John'} { ' n a m e ' : '
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v = str(object=iter([1, 2, 3])) # Iterator  print(v, v[0], v[1], v[2], v[3], v[4], v[5], v[6], v[7], v[8], v[9]) # <list_iterator object at 0x00000200F4715930> < l i s t _ i t e r
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v = str(object=lambda: 10) print(v, v[0], v[1], v[2], v[3], v[4], v[5], v[6], v[7], v[8], v[9]) # <function <lambda> at 0x00000200F3EA8E00> < f u n c t i o n
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v = b'H\xd1\x91ll\xcf\x86!' print(str(object=v, encoding='utf-8', errors='strict')) print(str(object=v, encoding='utf-8')) print(str(object=v, errors='strict')) # Hёllφ!
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v = b'H+BFE-ll+A8Y!' print(str(object=v, encoding='utf-7')) # Hёllφ!
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v = b'\xff\xfeH\x00Q\x04l\x00l\x00\xc6\x03!\x00' print(str(object=v, encoding='utf-16')) # Hёllφ!
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v = b'H\xc7\xcell\xa3p!' print(str(object=v, encoding='big5')) # Hёllφ!
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import codecs def hashreplace_handler(s): return ((s.end - s.start) * '#', s.end) codecs.register_error('hashreplace', hashreplace_handler) v = b'H\xd1\x91ll\xcf\x86!' print(str(object=v, encoding='ascii', errors='ignore')) # Hll!  print(str(object=v, encoding='ascii', errors='replace')) # H��ll��!  print(str(object=v, encoding='ascii', errors='hashreplace')) # H##ll##!  print(str(object=v, encoding='ascii')) print(str(object=v, encoding='ascii', errors='strict')) # UnicodeDecodeError: 'ascii' codec can't decode byte 0xd1 # in position 1: ordinal not in range(128)
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v = b'H&#1105;ll&#966;!' print(str(object=v, encoding='ascii', errors='xmlcharrefreplace')) # H&#1105;ll&#966;!
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v = b'H\\u0451ll\\u03c6!' print(str(object=v, encoding='ascii', errors='backslashreplace')) # H\u0451ll\u03c6!
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