程式結構

• 順序
• 選擇
• 迴圈

選擇（分支）語句

• if語句
• if 表示式：
  語句1
  語句2
  else：
  語句

a = input("請輸入數字：") #字串
a = int(a)
if a < 10:
    print("Python全棧課程")
else:
    print("Linux從入門到放棄")

請輸入數字：100
Linux從入門到放棄

#輸入成績，100-90分為優秀，89-80分為良好，79-60分為及格，60分以下為不及格
score = input("input your score:")
score = int(score)
if score <= 100 and score >= 90:
    print("優秀")
else:
    if score <= 89 and score >= 80:
        print("良好")
    else:
        if score <= 79 and score >=60:
            print("及格")
        else:
            print("不及格")       
 

input your score:99
優秀

score = input("input your score:")
score = int(score)
if score <= 100 and score >= 90:
    print("優秀")
elif score <= 89 and score >= 80:
    print("良好")
elif score <= 79 and score >=60:
    print("及格")
else:
    print("不及格")
 

input your score:99
優秀

pass關鍵字

• 佔位符

a = 1
if a < 2:

  File "<ipython-input-12-504e793a112e>", line 2
    if a < 2:
             ^
SyntaxError: unexpected EOF while parsing

a = 1
if a < 2:
    pass

a = 1
if a < 2:
    pass #跳過此語句，而不是終止
    print("pass")

pass
 

迴圈

• for迴圈
• while迴圈

list = [1,2,3,4]
for i in list:
    print(i)

1
2
3
4

list = [1,2,3,4]
for i in list:
    print("**********************")
    if i % 2 == 0:
        print("Python全棧課程")
    else:
        print("Linux從入門到放棄")
    print("**********************")

**********************
Linux從入門到放棄
**********************
**********************
Python全棧課程
**********************
**********************
Linux從入門到放棄
**********************
**********************
Python全棧課程
**********************

print(1)
print(2)#print()自動換行

1
2

print(1, end = "") #end的預設值為\n(換行)
print(2, end = "")

12

for i in range(1,101,2):#range:從1開始到100結束,步長為2
    print(i, end = " ")

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 

list = [1,2,3,4]
for i in list:
    print(i)
else:
    print("python全棧課程")
    print("Linux從入門到放棄")

1
2
3
4
python全棧課程
Linux從入門到放棄