2 Python Cheat Sheet

2.0.1 Mathematics

+ and -: addition and subtraction
* and /: multiplication and division
//: floor division
**: exponentials

2.0.2 Common Python Functions

print(): print a string to screen
type(): return the data type of an object

2.0.3 Comparisons

< and >: greater than, less than
<= and >=: greater than or equal to, less than or equal to

2.0.4 String Methods

.upper() and .lower(): Convert string to upper or lower case
.split(): Split a string on a delimiter into a list
.join(): Convert a list into a string using a delimiter
.rstrip(), .lstrip(), and .strip(): Remove unwanted characters from the right side, left side, or both sides of a string

2.0.5 Type Conversion

float(): Convert data to float
int(): Convert data to an integer
str(): Convert data to a string

2.0.6 Working with Files

open(file, mode): Most common modes are: (r), write (w), append (a)
.readlines(): Return a list where each element is a line from the input file
.close(): Close the file

2.0.7 List methods

.append(): Add an element to the end of a list

2.0.8 `Numpy`

loadtxt(): Import a file
array.shape: Return the number of rows and columns of a numpy array object
np.mean(): Return the mean of an array. Can use the axis argument for row and column means
np.std(): Return the standard deviation of an array. Can use the axis argument for row and column standard deviations
np.max(): Return the maximum value of an array. Can be used with axis
np.min(): Return the minimum value of an array. Can be used with axis

2.0.9 Plotting

plt.subplots(): Initialize a figure with at least one subplot
.scatter(): Create a scatter plot
.plot(): Create a line plot
.hist(): Create a histogram
.legend(): Add a legend to your figure
.set_xlabel() and ax.set_ylabel(): Set x and y labels for a subplot
.set_title(): Set a title for a subplot
.set_xlim() and .set_ylim(): Set x and y limits for a subplot
plt.show(): Display plot