python setting an array element with a sequence.

#PYTHON SETTING AN ARRAY ELEMENT WITH A SEQUENCE. CODE#

Sequence is given, playing computer, in the table: LineĬhange count to the next element in the list Look againĪt the output and see that it matches this sequence. Through the loop count is 1, then 2, and finally 3. Takes on the next value in the sequence, so the first time ( count here) may be used in the block, and each time through it

Sequence, so in this example the two lines in the indented blockĪre repeated three times. The block of lines is repeated once for each element of the Indented statements to repeat may use item Variables, will be called playing computer. Program in the proper order of execution, carefully, In this simple sequential code, that also follows the The order of execution will always be the order of the lines in the The result from line 5 confirms theĥ=3+2, using the value of x from the previous lineġ0=2*5 on the right, use the value of y from theħ=10-3 on the right, use the value of x and y from the Line 4 then changes x, using the latest value of y Statement uses the values of variables when the line startsĮxecuting (what is left after the previous line of the tableĮxecuted), but the assignment to the variable y on the left causesĪ change to y, and hence the updated value of y, 10, is shown in In line three we use the fact that the right side of an assignment Since x has the value 3 when line 2 starts, x+2 is the same as 3+2. The comment on the right summarizes what is happening.

Value is given to x, but y is still undefined. In the table below, statements are referred to by the numbers labeling Track of what changes to variables are made by each statement. Understand what happens, one step at a time. Particularly if you did not guess right, it is important to

#PYTHON SETTING AN ARRAY ELEMENT WITH A SEQUENCE. CODE#

X = 3 # simple sequential code y = x + 2 # updating two variables y = 2 * y x = y - x print ( x, y )Ĭan you predict the result? Run the program and check. Situation, where statements are just executed in textual order. To prepare for that weįirst follow how variables can be updated in an even simpler This will be particularly important in loops.

The value of already defined variables can be.

There are two Python statement types to do that: the simplerįor loops, which we take up shortly, and while loops, which Repetition, looping back over the same block of code again andĪgain. To keep a computer doing useful work we need Practically, we cannot write millions of instructions to keep Get a program that would run by itself for more than a fraction of With the techniques discussed so far, it would be hard to Modern computers can do millions or even billions of instructions a

Python setting an array element with a sequence.