python - 获取已打印python的文本内容

Question

假设我打印了以下代码

print("""
THE RUSSIAN PEASANT ALGORITHM
-----------------------------
times two values x and y together


""")

x=int(raw_input("raw_input x: "))
y=int(raw_input("raw_input y: "))

print("x"+" "*(10)+"y")

while x!=1:
      x=x/2
      y=y*2

      print(str(x)+" "*10+str(y))

这将打印算法的结果，与用户输入的数字相匹配。现在如果我希望获得一个包含所有已输出到 python 控制台的变量，我该怎么做呢？

编辑:为了澄清我想要输出的原因，基本上我可以用“CLS”清除屏幕并重新打印我已经打印的所有内容，但偶数 x 值被划掉，就像你应该对俄语所做的那样农民算法。

Answer 1

这一切都是关于将您的 stdout 重新定义为某个内存流。

您可以使用打印到string。参见 python2 docs - Reading and writing strings as file , python3 docs - Core tools for working with streams .

用那个字符串做你想做的事，甚至用常规的 print 打印它。

---

代码Python2:

import sys
import StringIO
old_stdout = sys.stdout # Memorize the default stdout stream
sys.stdout = buffer = StringIO.StringIO()

print('123')
a = 'HeLLo WorLd!'
print(a)
# Call your algorithm function.
# etc...

sys.stdout = old_stdout # Put the old stream back in place

whatWasPrinted = buffer.getvalue() # Return a str containing the entire contents of the   buffer.
print(whatWasPrinted) # Why not to print it?
buffer.close()

---

Python3代码:

import sys
import io

old_stdout = sys.stdout # Memorize the default stdout stream
sys.stdout = buffer = io.StringIO()

print('123')
a = 'HeLLo WorLd!'
print(a)
# Call your algorithm function.
# etc...

sys.stdout = old_stdout # Put the old stream back in place

whatWasPrinted = buffer.getvalue() # Return a str containing the entire contents of the buffer.
print(whatWasPrinted) # Why not to print it?
print(123)

---

whatWasPrinted 然后可以更改，打印到常规标准输出等。