3_2_string.py

'spam eggs'  # single quotes
'spam eggs'
'doesn\'t'  # use \' to escape the single quote...
"doesn't"
"doesn't"  # ...or use double quotes instead
"doesn't"
'"Yes," they said.'
'"Yes," they said.'
"\"Yes,\" they said."
'"Yes," they said.'
'"Isn\'t," they said.'
'"Isn\'t," they said.'

'"Isn\'t," they said.'
'"Isn\'t," they said.'
print('"Isn\'t," they said.')
# "Isn't," they said.
s = 'First line.\nSecond line.'  # \n means newline
s  # without print(), \n is included in the output
'First line.\nSecond line.'
print(s)  # with print(), \n produces a new line
# First line.
# Second line.


print('C:\some\name')  # here \n means newline!
# C:\some
# ame
print(r'C:\some\name')  # note the r before the quote
# C:\some\name

print("""\
Usage: thingy [OPTIONS]
     -h                        Display this usage message
     -H hostname               Hostname to connect to
""")

# 3 times 'un', followed by 'ium'
3 * 'un' + 'ium'
'unununium'

'Py' 'thon'
'Python'

text = ('Put several strings within parentheses '
         'to have them joined together.')
text
'Put several strings within parentheses to have them joined together.'

prefix = 'Py'
# prefix 'thon'  # can't concatenate a variable and a string literal
#   File "<stdin>", line 1
#     prefix 'thon'
#                 ^
# SyntaxError: invalid syntax
# ('un' * 3) 'ium'
#   File "<stdin>", line 1
#     ('un' * 3) 'ium'
#                    ^
# SyntaxError: invalid syntax

prefix + 'thon'
'Python'

word = 'Python'
word[0]  # character in position 0
'P'
word[5]  # character in position 5
'n'

word[-1]  # last character
'n'
word[-2]  # second-last character
'o'
word[-6]
'P'

word[0:2]  # characters from position 0 (included) to 2 (excluded)
'Py'
word[2:5]  # characters from position 2 (included) to 5 (excluded)
'tho'

word[:2] + word[2:]
'Python'
word[:4] + word[4:]
'Python'

word[:2]   # character from the beginning to position 2 (excluded)
'Py'
word[4:]   # characters from position 4 (included) to the end
'on'
word[-2:]  # characters from the second-last (included) to the end
'on'

word[42]  # the word only has 6 characters
# Traceback (most recent call last):
#   File "<stdin>", line 1, in <module>
# IndexError: string index out of range

word[4:42]
'on'
word[42:]
''

# word[0] = 'J'
# Traceback (most recent call last):
#   File "<stdin>", line 1, in <module>
# TypeError: 'str' object does not support item assignment
# word[2:] = 'py'
# Traceback (most recent call last):
#   File "<stdin>", line 1, in <module>
# TypeError: 'str' object does not support item assignment

'J' + word[1:]
'Jython'
word[:2] + 'py'
'Pypy'

s = 'supercalifragilisticexpialidocious'
len(s)
34