Python

Show text and numbers

1. 01Your first PythonUse print to put what you wrote up on the screen.7 slides · 13 exercisesGo to the exercises
2. 02Numbers and mathsLet Python do the sums. A number is written without quotes, unlike text.6 slides · 13 exercisesGo to the exercises
3. 03Dividing, and what is left overThere are three symbols for dividing. We will see why a tidy answer still comes out as a decimal.6 slides · 13 exercisesGo to the exercises
4. 04The order things happen inTimes first, brackets even sooner. Here is how to make Python work things out the way you meant.6 slides · 13 exercisesGo to the exercises
5. 05Joining text together+ is not only for numbers. It works on text too — but mix in a number and Python tells you off.6 slides · 13 exercisesGo to the exercises
6. 06Writing commentsEverything after # is ignored. Leave a note for the you of next week.6 slides · 13 exercisesGo to the exercises

Give a value a name

1. 07Making a variableGive a value a name, and you can call it back up as many times as you like.6 slides · 13 exercisesGo to the exercises
2. 08Why bother with variablesIt all runs without them, so why use them? Put the two side by side and see.6 slides · 13 exercisesGo to the exercises
3. 09Changing what is insideWhat is in a variable can be swapped out later. We will see why x = x + 1 makes sense.6 slides · 13 exercisesGo to the exercises
4. 10The shorter way to write itx = x + 1 can be written x += 1. It comes up so often that it is worth knowing.6 slides · 13 exercisesGo to the exercises
5. 11Dropping values into a sentenceWrite {} inside f"..." and the contents of a variable land there. It is the way you will write most often.6 slides · 13 exercisesGo to the exercises
6. 12Changing what kind of value it isThe text "10" and the number 10 are different things. Here are the tools for going between them.6 slides · 13 exercisesGo to the exercises

The rules of indentation

1. 13The rules of indentingIn Python the spaces at the start of a line mean something. Get this now and you will not trip later.6 slides · 13 exercisesGo to the exercises

Branch on a condition

1. 14Branching on a conditionWrite an if and your program has an opinion for the first time.6 slides · 13 exercisesGo to the exercises
2. 15Comparing bigger and smallerA comparison answers True or False. Let us open up a condition and look inside.6 slides · 13 exercisesGo to the exercises
3. 16Asking whether things are the same= puts in, == asks. This is the one beginners muddle most.6 slides · 13 exercisesGo to the exercises
4. 17The other roadWrite an else and you have somewhere to go when the condition does not hold.6 slides · 13 exercisesGo to the exercises
5. 18Splitting it more waysLine up some elifs and you can have three roads, or four, or as many as you need.6 slides · 13 exercisesGo to the exercises
6. 19Combining conditionsIn Python it is and, not &&. Being able to read it out loud is very Python.6 slides · 13 exercisesGo to the exercises
7. 20When there is nothing thereNone is the value for "nothing at all". We will also hand values straight to a condition.6 slides · 13 exercisesGo to the exercises