Question

我有一个包含

的logdata.txt文件

07/05/2016 11:39  0.00167
07/05/2016 11:39  0.00333
07/05/2016 11:39  0.00167
07/05/2016 11:40  0.00333
07/05/2016 11:40  0.005
07/05/2016 11:40  0.00667

我写了一个代码，它总结了第三列，输出是

07/05/2016 0.02167

此结果存储在senddata.txt

中

 f = open('logdata.txt','r+')

    res = OrderedDict()
    for line in f:
        values = line.split('')

        if len(values) == 4:
            date = values[0]
            val = values[3]
            if res.get(date):
                res[date] += int(val)            
            else:
                res[date] = int(val)

    f.close()


    f = open('senddata.txt', 'w')
    for line in res.keys():
        f.write('{} {}'.format(line, res[line]))
    f.close()

出现以下错误

Traceback (most recent call last):

    res[date] = int(val)
ValueError: invalid literal for int() with base 10: '0.00167\n'

任何人都可以帮我调试它......

Answer 1

从最后一个文字中删除“\ n”，以便将其转换为float。

val = values[3].split('\n')[0]
if res.get(date):
    res[date] += float(val)
else:
    res[date] = float(val)

Answer 2

问题是# Always use a with statement to open files, so it # closes automatically even if something goes wrong # You're not writing to the file so the default mode 'r' is fine with open('logdata.txt') as logdata: res = OrderedDict() for line in logdata: # Passing no arguments splits on whitespace and removes empty strings # so the result is intuitive and there's no need to 'clean' it values = line.split() # Note that the length is now 3, not 4 if len(values) == 3: # Tuple unpacking is sometimes much nicer than using an index # _ is the conventional way of saying 'a value I don't care about' date, _, val = values # Much nicer than an if statement # If .split() hadn't removed the whitespace the best thing to do # would be to remove it with val.strip() or val.rstrip() res[date] = res.get(date, 0) + float(val) # Again, not the with statement with open('senddata.txt', 'w') as f: # This is how to get both key and value at once # Even with your old method, 'for line in res:' is good enough # as iteration directly over a dict means over its keys for line, value in res.items(): f.write('{} {}'.format(line, value))这是换行符，当你逐行遍历文件时，它几乎总是出现在一行的末尾。我已经展示了如何修复它以及如何改进代码的其他方面。

if len(values) == 3

您可能希望删除date, _, val = lines.split()，因为如果不是这样，则可能表示您想要修复的无效数据，而不是静默地传递它。在这种情况下，您也可以说collections.defaultdict。

越来越先进，有一个更简洁的方法来处理默认的起始值0.通常你会使用OrderedDict，但如果你已经需要，这不是一个简单的选择class OrderedFloatDict(OrderedDict): def __missing__(self, key): return 0 ... res = OrderedFloatDict() ... res[date] += float(val)。因此，您可以手动获得相同的功能：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:text="Your Message: "
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <View
        android:layout_width="150dp"
        android:layout_height="1dp"
        android:layout_alignBottom="@+id/textView"
        android:layout_gravity="bottom"
        android:layout_toEndOf="@+id/textView"
        android:layout_toRightOf="@+id/textView"
        android:background="#FF0000FF" />

</RelativeLayout>

python 2.7中数据的提取和求和

2 个答案: