Computer Science Notes CS 114
Strings
General
string[x] - returns the character at that position in the string.
string[0:2] - returns the 1st and 2nd characters [incl. : excl.]
string[1:len(string)-1] - returns the middle of the string
len(string) - returns the length of the string. (cat = 3)
+ - concatenate string.
== - checks if the strings are the same.
.contains(str) - checks if a string contains a certain string
.index(str) - returns the position of the character in the string
Manipulative Methods
.upper() - converts the string to uppercase
.lower() - converts the string to lowercase
.casefold() - converts string to lowercase, includes additional characters
.replace(old, new, count) - replaces certain characters in a string with the new input
Ethan Ganz 1
, Arithmetic
Functions
+ - addition
- - subtraction
/ - normal division ( = 2.5)
// - floor division (5 // 2 = 2)
* - multiplication
**2 - to the power of 2 (**5 = to the power of 5)
Note: - Considers order of operation
print(str(x) + ‘ ‘ + str(y)) - prints “x y” (x and y are integers or floats)
Methods
max(a, b, c) - returns the variable with the largest value.
min(a, b, c) - returns the variable with the smallest value.
abs(x) - returns the absolute value of x.
abs(x) % 10 - returns the last digit of the number.
Math class
math.sqrt() - returns the square root of a float
math.exp(a) - e to the power of a
math.log(a, b) - log a with base b
math.pi - pie
math.e -e (2.718281828459045…)
Random class
random.random - random float between [0, 1)
random.uniform(a, b) - random float between [a, b] (or [a, b) )
random.int(a, b) - random int between [a, b]
random.range(a, b, c) - random int between [a, b) within the increment c
random.shuffle(a) - shuffles array a randomly (works with 1D or 2D array)
random.gauss(a, b) - Gaussian distribution (a = mu, b = sigma)
Ethan Ganz 2
Strings
General
string[x] - returns the character at that position in the string.
string[0:2] - returns the 1st and 2nd characters [incl. : excl.]
string[1:len(string)-1] - returns the middle of the string
len(string) - returns the length of the string. (cat = 3)
+ - concatenate string.
== - checks if the strings are the same.
.contains(str) - checks if a string contains a certain string
.index(str) - returns the position of the character in the string
Manipulative Methods
.upper() - converts the string to uppercase
.lower() - converts the string to lowercase
.casefold() - converts string to lowercase, includes additional characters
.replace(old, new, count) - replaces certain characters in a string with the new input
Ethan Ganz 1
, Arithmetic
Functions
+ - addition
- - subtraction
/ - normal division ( = 2.5)
// - floor division (5 // 2 = 2)
* - multiplication
**2 - to the power of 2 (**5 = to the power of 5)
Note: - Considers order of operation
print(str(x) + ‘ ‘ + str(y)) - prints “x y” (x and y are integers or floats)
Methods
max(a, b, c) - returns the variable with the largest value.
min(a, b, c) - returns the variable with the smallest value.
abs(x) - returns the absolute value of x.
abs(x) % 10 - returns the last digit of the number.
Math class
math.sqrt() - returns the square root of a float
math.exp(a) - e to the power of a
math.log(a, b) - log a with base b
math.pi - pie
math.e -e (2.718281828459045…)
Random class
random.random - random float between [0, 1)
random.uniform(a, b) - random float between [a, b] (or [a, b) )
random.int(a, b) - random int between [a, b]
random.range(a, b, c) - random int between [a, b) within the increment c
random.shuffle(a) - shuffles array a randomly (works with 1D or 2D array)
random.gauss(a, b) - Gaussian distribution (a = mu, b = sigma)
Ethan Ganz 2
