Python Basics Cheat Sheet

This Python Coding Basics Cheat Sheet is like a Python course all in an A4 page.

Variablesstring : e.g. variablename = "john'

string : e.g. variablename = john

integer: e.g. variablename = 0

float: e.g. variablename = 0.0

boolean: e.g. variablename = True

boolean: e.g. variablename = False

Print

print ("hello world")

print ("hello world", myvariable)

print ("hello world", myvariable, end ="")

Console input

myvariable = input("enter your name")

myvariable = int (input("enter your age? "))

myvariable = float( input("what is 3 / 4? ")

Decisions

#else and elif are optional

if condition:

#your code here

elif:

#your code here

else:

#your code here

Conditional Operators

> >= < <= == != not , in, and

e.g.:

a != b

not ( a==b)

a == 1 or a == b or a == c

a in (1,2,3)

Arithmetic operators

() * - + / % (modulus) ** ( exponential)

Assignment and Increments

= += *= -= /=

Lambda funtion

myvar = lambda arguments : expression

Loops

while condition:

#your code here

for i in range ( startvalue, stopvalue, increment):

#your code here

.Csv or .txt Files

myfile = open("filepath//filename.ext")

for line in myfile:

print (line)

#your code here

myfile.close()

Json Files

Write to a .json file

with open(`path//file.json`, `w`) as outputfile:

json.dump(mydict, outfile)

Read from a .json file

with open(`path//filename.json`) as inputfile:

mydict= json.load(json_data)

List and dictionaries

python coding basics has no built-in support for arrays,

but python lists can be used instead

list, e.g.: mylist = [1,2,3]

for i in range(0,le(mylist), 1):

print (i,mylist[i])

for value in mylist:

print(value)

dictionary (key -value pairs), e.g.:

mydict = {"name": "john", "age": 36 }

mydict.keys()

for key,val in mydict.items():

print (key,value)

Exception Handling

try:
#your code here

except:
#your code here

else:

#your code here
finally:
#your code

Lambda x = lambda a : a + 10