Python

1) length

len()- to calculate the length of the string
ex) len(text)

2) slicing

f[start:stop:step] - to extract the part of the strin to get specific range of the string )

ex)
f[:] - display the entire string
f[:stop] - display chars from the beginning of the string up to (but not including) the chars at the stop index.
f[start:] - display chars from start index to the end of the string
f[start:stop] - display chars from the start index up to (but not including) the character at the stop index.
f[start:stop:step] - display chars from the start index up to (but not including) the char at the stop index, with a step size of step
+) negative slicing starts the end of the string

3) split

split() - to split a string into a list

ex)
num='403-123-1234'
results = num.split('-')[0]
print(results)
-> 403

4) list & dictionary

can combine lists and dictionaries to create more complex data structures or to achieve specific data organization

4-1) List

when checking if the value is in the list, we can use 'in' keyword

+) can work with dictionary as well

4-2) Dictionary

-cannot be indexed using sequential integer indices because they are unordered collections of key-value pairs.
-can store values of various data types as their values

+)

#To print smith's science score 

people = [
    {'name': 'bob', 'age': 20, 'score':{'math':90,'science':70}},
    {'name': 'carry', 'age': 38, 'score':{'math':40,'science':72}},
    {'name': 'smith', 'age': 28, 'score':{'math':80,'science':90}},
    {'name': 'john', 'age': 34, 'score':{'math':75,'science':100}}
]

print(people[2]["score"]["science"])

5) def
is used when defining the function

6)tuple
ordered sequence of values
represented by a comma-delimited list whose values are enclosed in parentheses, although they're sometimes enclosed in square brackets or angle brackets.

a_dict = [('zeus','24'),('keria','29'),('faker','30')]

7)set
unordered, mutable collection of unique elements(no duplicated elements)
can perform union, intersection, difference

• union

• intersection

• difference

8) f-string
as a formatted string literals, it allows for concise and dynamic expression embedding within the string using the syntax f"...".

9) Ternary conditional expression
condensed the original code into one line using a ternary conditional expression

• In if statement
  ->even number

• In for loop

10) Map & Lambda & Filter

• map - a function that applies a specified operation to each item in an iterable (like a list) and returns an iterator over the results.

• A lambda - way to define small, anonymous functions. It is often used in conjunction with map to apply a simple operation to each element of an iterable.

In the provided example, map is used to apply a lambda function to categorize individuals in the people list as either 'adult' or 'teenager' based on their age. The lambda function defines this categorization condition. The final result is a new list containing the categorization results.

• filter - is used to selectively include elements from an iterable (like a list) based on a specified condition.It creates a new iterable containing only the elements that meet the specified criteria, determined by a filtering function or lambda function.