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LearnRemember   PYTHON





pag. 131-142

Raw strings

Raw strings prints any backslash in the string. 
 
"""Raw strings:
A raw string ignores all escape characters"""

print('That\'s my cat')
    # That's my cat

print(r'[a-z\'A-Z]')
    # [a-z\'A-Z]

Interpolation

You don't have to use str() to convert values to string. 
 
"""String interpolation:
The %s operator inside the string is a marker to be replaced.
"""

name = 'John'
age = 40
message = 'My name is %s and I\'m %s old'

print(message % (name, age))
    # My name is John and I'm 40 old

print("I am %s and have %s dogs " % ("John", 2))
    # I am John and have 2 dogs

F-String

In a f-string braces are used insteed of %s 
 
"""f-string:
Is similar to string interpolation, except that ...
braces are used insteed of %s
The same result can be obtain using format() method.
"""

name = 'John'
age = 40
message = f'My name is {name} and I\'m {age} old'

print(message)
    # My name is John and I'm 40 old

print('My name is {} and I am {} old'.format(name, age))
    # My name is John and I am 40 old

print('My name is {0}'.format(name, age))
    # My name is John

Format Decimals 

 
""" FORMAT DECIMALS
-------------------
"""

A = [1, 2, 3]
avg = sum([1, 3])/len([1,3])

print(f"{avg:.2f}")  # 2.00

Strip

Strip off whitespace characters (\s, \t, \n) 
 
"""Removing white spaces:
Use strip(), rstrip() and lstrip() ...
to strip off whitespace characters (\s, \t, \n)
"""

HELLO = ' Hello World '
HELLO_STRIP = HELLO.strip()
HELLO_LSTRIP = HELLO.lstrip()
HELLO_RSTRIP = HELLO.rstrip()

assert f'x{HELLO_STRIP}x' == 'xHello Worldx'
assert f'x{HELLO_LSTRIP}x' == 'xHello World x'
assert f'x{HELLO_RSTRIP}x' == 'x Hello Worldx'




References: