Python教學(2) if for while

Python教學(2)

IF Statement

IF Statement

Python supports the usual logical conditions from mathematics:

• Equals: a == b

• Not Equals: a != b

• Less than: a < b

• Less than or equal to: a <= b

• Greater than: a > b

• Greater than or equal to: a >= b

IF Statement

• if

• if...else

• if...elif...else

IF (單向)

IF...ELSE...(雙向)

IF...ELIF...(多重條件)

IF...ELIF...ELSE(多重條件)

Multiple Choice

圖中的程式能否正確執行?

• 可正常執行

• 無法執行

Multiple Choice

圖中的程式能否正確執行?

• 可正常執行

• 無法執行,

  因缺少了標點符號

• 無法執行,

  因if 條件句缺少了縮排

Multiple Choice

執行圖中的程式結果為何?

• 印出A

• 印出B

• 沒有印出任何結果

While Loops

​while 條件
執行程式

While Loops

While Loops---break

​結果:
1
2
3

While Loops---break

​結果:
1
2
4
5
6

Fill in the Blank

In the loop, when i is 3, jump directly to the next iteration.

Fill in the Blank

Print a message once the condition is false.

:

For Loops(列印lists中的元素)

For Loops(列印字串中的字母)

For Loops(列印字串中的字母)

For Loops(列印數字範圍)

​Note that range(6) is not the values of 0 to 6, but the values 0 to 5.

For Loops(列印數字範圍)

​range(2, 6), which means values from 2 to 6 (but not including 6):

Multiple Choice

執行圖中的程式結果為何?

• Exit the loop when x is "cherry"

• Only print "apple"

• Print "apple" and "banana"

• Print all elements

Multiple Choice

執行圖中的程式結果為何?

• Exit the loop when x is "cherry"

• Only print "apple"

• Print "apple" and "banana"

• Print all elements

Multiple Choice

執行圖中的程式結果為何?

• 0

  1

  2

  3

• 1

  2

  3

  4

• 2

  3

  4

  5

• 3

  4

  5

  6

For inner Loops(巢狀回圈)