<p>您应该用<a href="https://docs.python.org/3/tutorial/" rel="nofollow noreferrer">tutorial(s)</a>来学习python编码-这个问题是python的基本问题。你知道吗</p>
<p>创建一个检查变量并打印正确内容的函数:</p>
<pre><code>x1 = .2
x2 = .33
x3 = -.422
x4 = -1
def check_and_print(value, variablename):
"""Checks if the content of value is smaller, bigger or euqal to zero.
Prints text to console using variablename."""
if value > 0:
print(f"{variablename} is positive")
elif value < 0:
print(f"{variablename} is negative")
else:
print(f"{variablename} is zero")
check_and_print(x1, "x1")
check_and_print(x2, "x2")
check_and_print(x3, "x3")
check_and_print(x4, "x4")
check_and_print(0, "carrot") # the given name is just printed
</code></pre>
<p>输出:</p>
<pre><code>x1 is positive
x2 is positive
x3 is negative
x4 is negative
carrot is zero
</code></pre>
<p>通过使用<code>list</code>的<code>tuples</code>和循环,可以进一步缩短代码:</p>
<pre><code>for value,name in [(x1, "x1"),(x2, "x2"),(x3, "x3"),(x4, "x4"),(0, "x0")]:
check_and_print(value,name) # outputs the same as above
</code></pre>
<p>独行:</p>
<ul>
<li><a href="https://docs.python.org/3/tutorial/controlflow.html#defining-functions" rel="nofollow noreferrer">functions</a></li>
<li><a href="https://docs.python.org/3/tutorial/datastructures.html#tuples-and-sequences" rel="nofollow noreferrer">tuples</a></li>
<li><a href="https://docs.python.org/3/tutorial/introduction.html#lists" rel="nofollow noreferrer">lists</a></li>
<li><a href="https://docs.python.org/3/tutorial/datastructures.html#looping-techniques" rel="nofollow noreferrer">loops</a></li>
<li><a href="https://docs.python.org/3/library/string.html#custom-string-formatting" rel="nofollow noreferrer">string formatting</a></li>
</ul>