 ## String Functions

Python contains many useful built-in functions and methods to accomplish common tasks.
join – joins a list of strings with another string as a separator.
replace – replaces one substring in a string with another.
startswith and endswith – determine if there is a substring at the start and end of a string, respectively.
To change the case of a string, you can use lower and upper.
The method split is the opposite of join, turning a string with a certain separator into a list.
Some examples:

print(“, “.join([“spam”, “eggs”, “ham”]))
#prints “spam, eggs, ham”

print(“Hello ME”.replace(“ME”, “world”))
#prints “Hello world”

print(“This is a sentence.”.startswith(“This”))
# prints “True”

print(“This is a sentence.”.endswith(“sentence.”))
# prints “True”

print(“This is a sentence.”.upper())
# prints “THIS IS A SENTENCE.”

print(“AN ALL CAPS SENTENCE”.lower())
#prints “an all caps sentence”

print(“spam, eggs, ham”.split(“, “))
#prints “[‘spam’, ‘eggs’, ‘ham’]”

## Numeric Functions

To find the maximum or minimum of some numbers or a list, you can use max or min.
To find the distance of a number from zero (its absolute value), use abs.
To round a number to a certain number of decimal places, use round.
To find the total of a list, use sum.
Some examples:

print(min(1, 2, 3, 4, 0, 2, 1))
print(max([1, 4, 9, 2, 5, 6, 8]))
print(abs(-99))
print(abs(42))
print(sum([1, 2, 3, 4, 5]))

Result:

>>
0
9
99
42
15
>>>

## List Functions

Often used in conditional statements, all and any take a list as an argument, and return True if all or any (respectively) of their arguments evaluate to True (and False otherwise).
The function enumerate can be used to iterate through the values and indices of a list simultaneously.
Example:

nums = [55, 44, 33, 22, 11]

if all([i > 5 for i in nums]):
print(“All larger than 5”)

if any([i % 2 == 0 for i in nums]):
print(“At least one is even”)

for v in enumerate(nums):
print(v

Result:

>>
All larger than 5
At least one is even
(0, 55)
(1, 44)
(2, 33)
(3, 22)
(4, 11)
>>>

NOTE!
You can try it yourself using a Python code editor.

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