Syntax cheat sheet

In [ ]:
# Functions: they are only run when called and are used to repeat work

# A function can have 0, 1, or as many arguments as you want.
def FUNCTION_NAME(ARGUMENT1, ARGUMENT2, ...):
    FUNCTION_BODY # Optional
    return FUNCTION_VALUE # Technically optional, but you should always put a return
In [2]:
# Examples of functions

# The identity function
def identity(x):
    return x

# A function that sums 0 to x, inclusive
def sumToXInclusive(x):
    s = 0
    for i in range(x + 1):
        s += i
    return 
In [3]:
# Example of calling a function

sumToXInclusive(5)
Out[3]:
15
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# Control flow: control flow is used to change the behavior of a program based on a condition

# CONDITION are expressions that result in boolean values

# Exactly 0 or 1 of the bodies will execute
# While elif and else are optional, if you have them, the bodies are not

if CONDITION1:
    IF_BODY # NOT optional
# elifs are optional, and you can have as many of them as you want
elif CONDITION2:
    ELIF_BODY
# the else is optional and is a catch all. If no other bodies execute, the else body will execute
else:
    ELSE_BODY
In [ ]:
# Examples of control flow

if True:
    print('This will print')
    
    
if False:
    print('This will NOT print')
else:
    print('This will print')
    
    
if True:
    print('This will print')
elif True:
    print('This will NOT print')
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# For loops: used for repetitive behavior over an array, string, or range

for VARIABLE in {LIST, STRING, range}:
    LOOP_BODY
In [ ]:
# Examples of for loops

for i in [4, 6, 1]:
    print(i)
    
    
for x in 'mango':
    print(x)
    

for x in range(5):
    print(x)
In [ ]:
# While loops: used for repetitive behavior

# WARNING: they can run forever, be careful of how you use them

while CONDITION:
    WHILE_LOOP_BODY
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# While loop example

i = 0
while i < 10:
    print(i)
    i += 1