String Datatype
r before string means raw string, won’t be parsed.
print(r'C:\some\name') # note the r before the quote
C:\some\nameTwo or more string literals = concatenated
'Py' 'thon'
'Python'
text = ('Put several strings within parentheses '
... 'to have them joined together.')
'Put several strings within parentheses to have them joined together.'Documentation Strings
>>> def my_function():
... """Do nothing, but document it.
... No, really, it doesn't do anything.
... """
... pass
...
>>> print(my_function.__doc__)
Do nothing, but document it.
No, really, it doesn't do anything.String Manipulation
str.join()
delimiter = ","
csv_str = delimiter.join(['a', 'b', 'c'])
print(csv_str)
# a,b,c
text = ['Python', 'is', 'a', 'fun', 'programming', 'language']
print(' '.join(text))
# Output: Python is a fun programming languagerepr() And str()
When you don’t need fancy output but just want a quick display of some variables for debugging purposes, you can convert any value to a string with the repr() or str() functions.
The str() function is meant to return representations of values which are fairly human-readable, while repr() is meant to generate representations which can be read by the interpreter (or will force a SyntaxError if there is no equivalent syntax).
>>> s = 'Hello, world.'
>>> str(s)
'Hello, world.'
>>> repr(s)
"'Hello, world.'"
>>> str(1/7)
'0.14285714285714285'
>>> x = 10 * 3.25
>>> y = 200 * 200
>>> s = 'The value of x is ' + repr(x) + ', and y is ' + repr(y) + '...'
>>> print(s)
The value of x is 32.5, and y is 40000...
>>> # The repr() of a string adds string quotes and backslashes:
... hello = 'hello, world\n'
>>> hellos = repr(hello)
>>> print(hellos)
'hello, world\n'
>>> # The argument to repr() may be any Python object:
... repr((x, y, ('spam', 'eggs')))
"(32.5, 40000, ('spam', 'eggs'))"Format String
>>> year = 2016
>>> event = 'Referendum'
>>> f'Results of the {year} {event}'
'Results of the 2016 Referendum'str.format()
>>> yes_votes = 42_572_654
>>> no_votes = 43_132_495
>>> percentage = yes_votes / (yes_votes + no_votes)
>>> '{:-9} YES votes {:2.2%}'.format(yes_votes, percentage)
' 42572654 YES votes 49.67%'Other modifiers can be used to convert the value before it is formatted. '!a' applies ascii(), '!s' applies str(), and '!r' applies repr():
>>> animals = 'eels'
>>> print(f'My hovercraft is full of {animals}.')
My hovercraft is full of eels.
>>> print(f'My hovercraft is full of {animals!r}.')
My hovercraft is full of 'eels'.str.strip()
remove match
txt = ",,,,,rrttgg.....banana....rrr"
x = txt.strip(",.grt")
print(x)
banana