Question

我有一个程序从txt文件调用信息。文本文件中的每一行对应于不同目录中的整个文件。我想从txt文件（第1行）读取信息，并将其写入输出文件，其中包含目录（文件1）中相应文件的信息。我需要我的代码来处理多个文件。如何让每个循环相互对应以产生正确的输出？

import datetime
import glob

f = open('\\_spec_final.t15', 'w')
infofile = open('info.txt', 'rt')
num_lines = sum(1 for line in 'info.txt')
count = 0
while count <= num_lines
    for line in infofile: 
        lat = float(line[88:94]) 
        lon = float(line[119:127])
        year = int(line[190:194])
        month = int(line[195:197])
        day = int(line[198:200])
        hour = int(line[201:203])
        minute = int(line[204:206])
        second = int(line[207:209])
        dur = float(line[302:315])
        numpoints = float(line[655:660])
        fov = line[481:497] # field of view?
        sza = float(line[418:426])
        snr = 0.0000 
        roe = 6396.2 
        res = 0.5000
        lowwav = float(lowwav)
        highwav = float(highwav)
        spacebw = (highwav - lowwav)/ numpoints

        d = datetime.datetime(year, month, day, hour, minute, second)
        f.write('{:>12.5f}{:>12.5f}{:>12.5f}{:>12.5f}{:>8.1f}'.format(sza,roe,lat,lon,snr)) # line 1
        f.write("\n")
        f.write('{:>10d}{:>5d}{:>5d}{:>5d}{:>5d}{:>5d}'.format(year,month,day,hour,minute,second)) # line 2
        f.write("\n")
        f.write( ('{:%Y/%m/%d %H:%M:%S}'.format(d)) + "UT Solar Azimuth:" + ('{:>6.3f}'.format(sza)) + " Resolution:" + ('{:>6.4f}'.format(res)) + " Duration:" + ('{:>6.2f}'.format(dur))) # line 3
        f.write("\n")
        f.write('{:>21.13f}{:>26.13f}{:>24.17e}{:>12f}'.format(lowwav,highwav,spacebw,numpoints)) # line 4
        f.write("\n")

        path = '/Users/140803/*' 
        files = glob.glob(path)
        for file(count) in files:
            g = open(file, 'r')
            #do stuff
            g.close()

f.close()
infofile.close()

Answer 1

根据对话，您似乎根本不需要内循环。您有多个不需要存在的嵌套循环。我已经在这里重写了部分代码。

具体来说，如果您想迭代某些内容并同时计算，请不执行类似

的操作

for count in range(3):
    for item in iterator:
        print("%d %s" % (count, item))

这些循环的输出类似于

0 item1
0 item2
0 item3
1 item1
1 item2
1 item3
2 item1
2 item2
2 item3

你做想要的是enumerate函数，它在你的迭代器旁边运行一个计数器：

for count, item in enumerate(iterator):
    print("%d %s" % (count, item))

这将打印

0 item1
1 item2
2 item3

此外，我将所有open() ... close()构造替换为with ...：

import datetime
import glob

path = '/Users/140803/*' 
files = glob.glob(path)

with open('\\_spec_final.t15', 'w') as f:
    with open('info.txt', 'rt') as infofile:
        for count, line in enumerate(infofile): 
            lat = float(line[88:94]) 
            lon = float(line[119:127])
            year = int(line[190:194])
            month = int(line[195:197])
            day = int(line[198:200])
            hour = int(line[201:203])
            minute = int(line[204:206])
            second = int(line[207:209])
            dur = float(line[302:315])
            numpoints = float(line[655:660])
            fov = line[481:497] # field of view?
            sza = float(line[418:426])
            snr = 0.0000 
            roe = 6396.2 
            res = 0.5000
            lowwav = float(lowwav)
            highwav = float(highwav)
            spacebw = (highwav - lowwav)/ numpoints

            d = datetime.datetime(year, month, day, hour, minute, second)
            f.write('{:>12.5f}{:>12.5f}{:>12.5f}{:>12.5f}{:>8.1f}'.format(sza,roe,lat,lon,snr)) # line 1
            f.write("\n")
            f.write('{:>10d}{:>5d}{:>5d}{:>5d}{:>5d}{:>5d}'.format(year,month,day,hour,minute,second)) # line 2
            f.write("\n")
            f.write( ('{:%Y/%m/%d %H:%M:%S}'.format(d)) + "UT Solar Azimuth:" + ('{:>6.3f}'.format(sza)) + " Resolution:" + ('{:>6.4f}'.format(res)) + " Duration:" + ('{:>6.2f}'.format(dur))) # line 3
            f.write("\n")
            f.write('{:>21.13f}{:>26.13f}{:>24.17e}{:>12f}'.format(lowwav,highwav,spacebw,numpoints)) # line 4
            f.write("\n")

            with open(files[count], 'r') as g:
                #do stuff (to g presumably)

虽然在files上使用计数器实际上可能是您想要的，但我发现这种情况极不可能。我认为您实际上是在尝试根据刚加载的信息生成文件名并打开它。 globbing的问题在于它甚至不能保证在同一程序的两次不同运行之间以相同的顺序返回结果。

Answer 2

运行awakeFromNib后，override func awakeFromNib() { super.awakeFromNib() picker.dataSource = self picker.delegate = self //Your Code Below }包含文件名字符串列表。运行files = glob.glob(path)时，变量files将包含字符串文件名。因此，您可以按如下方式修改循环：

for file in files:

没有必要使用计数器，因为循环已遍历文件名中的每个文件。

循环内部循环并发

2 个答案: