The Variable

用 hash symbol （井字鍵）加comment

The equal sign means assignment.

Strings

single quote 或 double quote，沒加的話電腦以為是Variable

EOL means end of line.

不能把字串直接加數字

e.g.

print ‘my age is ’ + 9

可能用* 的

e.g.

print ‘!’ * 12

Indexing String

裡面的數字還可以放負數

Indexing String的延伸

用冒號抓出中間的字串

沒寫後面代表到end

沒寫前面代表從頭抓

單寫: 就是全部

Selecting Sub Sequences

有趣的練習測試，找出能代表完整Variable的寫法

在Empty String（字串內什麼都沒有）中，任何位置都是Error，對於範圍卻是空字串

Find strings in strings

找不到就顯示負1

大小寫會影響s

Find empty string always is zero.

有’’和沒有’’意義差很大，一個是從上方定義的變數找，一個是從‘’內的字串找

最後一個是變成，要找的字串比原本定義的多，當然就找不到

Practice with string.find()

print "test"[2:]

會印出 st

print "text".find("") # prints 0
print "text".find("") # prints -1

有趣的思考

print "Example 3: Printing out everything after a certain substring"

my_string = "My favorite color: blue"

color_start_location = my_string.find("color:")

favorite_color = my_string[color_start_location:]

print favorite_color # oops, this line prints out 'color: ' as well...

print favorite_color[7:] # this fixes it!

Finding substrings with parameter of number

number代表從哪裏開始找

Strings觀念考題

But ifsis the''empty string, thens[0]will cause an error because there is no character at position 0.

2.2 The Variable