Accessing Items in a List

Consider a Circuit with Resistors in Series

Let’s use a circuit with 9 volts of energy and three different resistors in series.

Let’s use nested lists to store information about the circuit.

# create each list individually before nesting
r1 = [3, "series", 1, 2]
r2 = [10, "series", 2, 3]
r3 = [5, "series", 3, 4]

# make a nested list of the resistors in the circuit
circuitSeries = [r1, r2, r3]

Ohm’s Law shows that the voltage (E) is equal to current (I) multiplied by resistance (R).

\(E = IR\)

Let’s apply Ohm’s Law to find the current going through each resistor and append it to the nested list.

# voltage through the circuit
V = 9

# current through first resistor
circuitSeries[0].append(V / circuitSeries[0][0])

print(circuitSeries[0])

[3, 'series', 1, 2, 3.0]

# total resistance and current
totalResistance = 0

for resistor in circuitSeries:
    totalResistance += resistor[0]

print(totalResistance)

18