# SOME EXAMPLES WITH STRINGS:
print(f'Prefixet f, f-String, formaterar talet 3.1415927 till 3 decimaler:')
print(f'{3.1415927 :.3f}\n')
print('Eller till 3 decimelr, put right in 8 positions:')
print(f'{3.1415927 :8.3f}\n')

print("""With so called "triple-quoted strings" a text
reach several lines""")
#

print('\t Gives a tab, while \n gives a line')
print('\a ger bell (somewhat irriteting...)\n')
print("Use end=' '", end='')
print("if you don't want a new line.", )
x=2
print(x, x*2, x+3, x**4, sep=' and also ') # OR sep=', ' OR sep='\n’

namn = 'Svea Lundmark' # print(type(namn)) gives <class 'str'>

print('\nA FEW EXAMPLES ON FUNCTIONS WITH STRING PARAMETERS:')
print('There are', len(namn), 'characters in the string "namn".') 
print('Make a list of the string "Nils": ', list("Nils")) 
print('We sort the string: ', sorted(namn)) # returns a sorted list.
print('After sorting: ', namn)
print('Largest character:', max(namn)) 

print('\nSOME METHODS IN THE STRING-CLASS:') 
print('The letter a exists', namn.count('a'), 'times.') 
print('The letter v on position ', namn.index('v')) 
print('Make all letter lower case:', namn.casefold())
# print(namn.upper().isupper()) #
print('Are are lettters upper case?', namn.isupper()) # False. 

print('\SOME OPERATORA IN STRINGS: =, +, *, in')
print('First concatenate with the + operator:')
namn += '–Granström' # + operator: concatenating
print(namn)
print('Then * operatorn:')
namn += 2 * ":-)" # * operator
print(namn)

print('\nTest the operator "in" ')
not_letters = []
for b in namn:
    if not b.isalpha(): # If b not a letter 
        not_letters.append(b)
print('Characters that are not letters:', not_letters)