Symbols and functions

Writing values

• Numbers are typed plainly: 7, 3.5, -2.
• Text goes in double quotes: "hello". Single quotes don't work.
• Value names are one word, with no quotes: score, firstName.
• true and false are the answers to yes-or-no questions.
• Lists go in square brackets: ["red", "blue"], or [] for an empty one. colours[1] is the first item.

1a = int(input("First number? "))2b = int(input("Second number? "))3print("The sum is " + str(a + b))

Symbols

1import math2
3
4def remainder_of(a, b):5    # Like % in B4Coder: the remainder has the sign of a, so -7 % 3 is -1 (Python's % gives 2).6    r = abs(a) % abs(b)7    return -r if a < 0 else r8
9
10sweets = 1711friends = 512print("Each gets " + str(math.floor(sweets / friends)))13print("Left over: " + str(remainder_of(sweets, friends)))

Handy functions

Use them in any box, like round(price, 2). Each does a small job and gives back the answer.

round(number) or round(number, digits)

Rounds to the nearest whole number, or to that many decimal places.

floor(number)

Rounds down to a whole number.

ceil(number)

Rounds up to a whole number.

abs(number)

Makes a number positive: abs(-5) is 5.

sqrt(number)

Square root: sqrt(16) is 4.

power(number, times)

Multiplies a number by itself: power(2, 3) is 8.

min(a, b, …) or min(list)

The smallest of some numbers, or of a list.

max(a, b, …) or max(list)

The biggest of some numbers, or of a list.

random(lowest, highest)

A random whole number between the two, including both.

length(list or text)

How many items are in a list, or letters in some text.

upper(text)

The text in CAPITAL letters.

lower(text)

The text in small letters.

contains(list or text, thing)

True if the list has that item, or the text has those letters: contains("hello", "ell").

join(list) or join(list, between)

Turns a list into text: join(["a", "b"]) is "a, b".

split(text) or split(text, between)

Cuts text into a list: split("red blue green") is ["red", "blue", "green"]. Say what to cut at: split("a-b", "-").

1import math2
3
4def round_half_up(x, digits=0):5    # Like round() in B4Coder: a half goes up, so 2.5 is 3 (Python's round() gives 2).6    scale = 10 ** digits7    whole = math.floor(x * scale)8    if x * scale - whole >= 0.5:9        whole += 110    return whole if digits == 0 else whole / scale11
12
13word = "banana"14print(word.upper())15print(len(word))16print(round_half_up(3.7))