String Basics
what is the purpose of the function len()?
The function len(), which stands for length(variable), is meant to find the number of characters in a variable.
For example:
hollowing = '31/October'
print(len(hollowing)) output: 10
Are dictionary mutable?
Yes. You can change the content of the key and variable.
What function formatting is used to find a character from a variable by knowing its index number?
Hint: it is the opposite of len()
print(variable[index])
For example:
hollowing = '31/October'
print(hollowing[0:2]) output: 31
* 0:2 = [0,2)
prices = {'apples': 1.99, 'oranges': 1.49}
print(f"The price of apples is {prices['kiwi']}")
what is the output?
Traceback (most recent call last): File "main.py", line 3, in <module> print(f"The price of apples is {prices['kiwi']}") ~~~~~~^^^^^^^^ KeyError: 'kiwi'
If it doesn't exist, then you can't use it.
how can you output a simple string with a variable?
print('string'/ Varble + 'string' / Varble)
for Example:
hollowing = '31/October'
print('what date is hollowing in 2024: ' + hollowing)
output: what date is hollowing in 2024: 31/October
prices = {'apples': 1.99, 'oranges': 1.49}
del prices ['apples']
what is the output?
There is no output. we did not have a print statement.
print(prices)
output: {'oranges': 1.49}
what does the format string do? And how do you construct one?
The format string is the same as the + function. It allows you to add variables to strings in the same print statement.
For Example:
a = '5'
b = '6'
print(f'The sum of {a} and {b} is {a + b}.')
print('The sum of ' + a + ' and ' + b + ' is ' + a + b +'.')
a = 'abc'
b = 'def'
print(f'The sum of {a} and {b} is {a + b}.')
print('The sum of ' + a + ' and ' + b + ' is ' + a + b +'.')
what is the syntax of dictionary?
Hint: You have a variable that is assigned to key(s) and those key(s) are assigned to a value(element).
Varble = {key:value}
Letters = 'key' or 'value'
Numbers = NO quotes on key or values
For example:
jet = {'jet1':'f-35', 'jet2':'f-22',52: 35, 53:42,}
print(jet['jet1'],jet[52],jet['jet2'])
output: f-35 35 f-22
lists are mutable [you can modify them after they are created]. How can you construct a list using list methods?
Hint: remove() or pop() = removes an element from a variable
append() = add an element to a variable
variable = elements
print(Varble)
list method.variable(elements)
print(variable)
For example:
jet = ['f-12', 'f-22']
print(jet)
jet.append('t-99')
print(jet)
*Notice: [] = lists {} = sets
How do you access a dictionary entry or a key value using f-string?
Hint: Dictionary entries cannot be accessed by indexing.
variable['key']
prices = {'apples': 1.99, 'oranges': 1.49}
print(f"The price of apples is {prices['apples']}")
output: The price of apples is 1.49
( ${prices['apples']}.:2f ) for $1.49