Python测试人员需要掌握的知识

a、字符串的定义方法

使用单引号（'）

你可以用单引号指示字符串，就如同'Quote me on this'这样。所有的空白，即空格和制表符都照原样保留。

使用双引号（"）

在双引号中的字符串与单引号中的字符串的使用完全相同，例如"What's your name?"。

使用三引号（'''或"""）

利用三引号，你可以指示一个多行的字符串。你可以在三引号中自由的使用单引号和双引号。例如：

'''This is a multi-line string. This is the first line.
This is the second line.
"What's your name?," I asked.
He said "Bond, James Bond."
'''

转义符

用\'来指示单引号——注意这个反斜杠。现在你可以把字符串表示为'What\'s your name?'。

表示这个特别的字符串的方法是"What's your name?"，即用双引号或三引号。

在一个字符串中，行末的单独一个反斜杠表示字符串在下一行继续，而不是开始一个新的行。例如：

"This is the first sentence.\
This is the second sentence."

b、变量

定义变量的方法与其它语言类似，变量的类型是通过赋值来确定的

Int型   Number = 0
字符串型 String = ‘'
Dict型  dict = {}

c、缩进

同一层次的语句必须有相同的缩进。每一组这样的语句称为一个块

i = 5
 print 'Value is', i
print 'I repeat, the value is', i

 d、运算符

最常用的是小（等）于、大（等）于、（不）等于、not、and、or

e、控制流

if语句

number = 23
guess = int(raw_input('Enter an integer : '))

if guess == number:
  print 'Congratulations, you guessed it.' # New block starts here
  print "(but you do not win any prizes!)" # New block ends here
elif guess < number:
  print 'No, it is a little higher than that' # Another block
  # You can do whatever you want in a block ...
else:
  print 'No, it is a little lower than that'
  # you must have guess > number to reach here

print 'Done'
# This last statement is always executed, after the if statement is executed

if 'a' in name:
  print 'Yes, it contains the string "a"'

elif和else部分是可选的

while语句

number = 23
running = True
while running:
  guess = int(raw_input('Enter an integer : '))
  if guess == number:
    print 'Congratulations, you guessed it.'
    running = False # this causes the while loop to stop
  elif guess < number:
    print 'No, it is a little higher than that'
  else:
    print 'No, it is a little lower than that'
else:
  print 'The while loop is over.'
  # Do anything else you want to do here
print 'Done'

for语句

for i in range(1, 5):
print i
等价于
for i in range(5):
print i

for循环在这个范围内递归——for i in range(1,5)等价于for i in [1, 2, 3, 4]，这就如同把序列中的每个数（或对象）赋值给i，一次一个，然后以每个i的值执行这个程序块

break语句

while True:
  s = raw_input('Enter something : ')
  if s == 'quit':
    break
  print 'Length of the string is', len(s)
print 'Done'

continue语句

while True:
  s = raw_input('Enter something : ')
  if s == 'quit':
    break
  if len(s) < 3:
    continue
print 'Input is of sufficient length'