将字符串拆分为空格列表，当下一个字符不是破折号时不包括单个空格 [英] Split string into a list on whitespace, excluding single spaces when the next character is not a dash
问题描述
我正在抓取一个具有卫星价值表的网站( https://planet4589.org/space/gcat/data/cat/satcat.html ).
I'm scraping a website that has a table of satellite values (https://planet4589.org/space/gcat/data/cat/satcat.html).
因为每个条目仅由空格分隔，所以我需要一种将数据条目的字符串拆分为数组的方法.
Because every entry is only separated by whitespace, I need a way to split the string of data entries into an array.
但是， .split()函数不适合我的需要，因为某些数据条目带有空格(例如 Able 3 )，我不能只是将所有内容都用空格分隔.
However, the .split() function does not suit my needs, because some of the data entries have spaces (e.g. Able 3), I can't just split everything separated by whitespace.
但是，这变得更加棘手.在没有可用数据的一些情况下，使用破折号(-").如果两个数据条目之间仅用一个空格隔开，并且其中一个是破折号，我不想将其作为一个条目包含.
It get's trickier, however. In some cases where no data is available, a dash ("-") is used. If two data entries are separated by only a space, and one of them is a dash, I don't want to include it as one entry.
例如说我们有两个条目" Able 3 "和"-"，仅用一个空格分隔.在文件中，它们将显示为" Able 3-".我想将此字符串拆分为单独的数据条目" Able 3 "，和"-"(作为列表，这将是 ["Able 3"，-"] ).
e.g say we have the two entries "Able 3" and "-", separated only by a single space. In the file, they would appear as "Able 3 -". I want to split this string into the separate data entries, "Able 3" and "-" (as a list, this would be ["Able 3", "-"]).
另一个示例是需要拆分" data1-"转换为 ["data1"，-"]
Another example would be the need to split "data1 -" into ["data1", "-"]
几乎，我需要将一个字符串分成一个列表或由空格分隔的单词，除非单词之间只有一个空格，并且其中一个不是破折号.
Pretty much, I need to take a string and split it into a list or words separated by whitespace, except when there is a single space between words, and one of them is not a dash.
此外，如您所见，表格很大.我曾想过要遍历每个字符，但这太慢了，我需要运行数千次.
Also, as you can see the table is massive. I thought about looping through every character, but that would be too slow, and I need to run this thousands of times.
以下是文件开头的示例:
Here is a sample from the beginning of the file:
JCAT Satcat Piece Type Name PLName LDate Parent SDate Primary DDate Status Dest Owner State Manufacturer Bus Motor Mass DryMass TotMass Length Diamete Span Shape ODate Perigee Apogee Inc OpOrbitOQU AltNames
S00001 00001 1957 ALP 1 R2 8K71A M1-10 8K71A M1-10 (M1-1PS) 1957 Oct 4 - 1957 Oct 4 1933 Earth 1957 Dec 1 1000? R - OKB1 SU OKB1 Blok-A - 7790 7790 7800 ? 28.0 2.6 28.0 Cyl 1957 Oct 4 214 938 65.10 LLEO/I -
S00002 00002 1957 ALP 2 P 1-y ISZ PS-1 1957 Oct 4 S00001 1957 Oct 4 1933 Earth 1958 Jan 4? R - OKB1 SU OKB1 PS - 84 84 84 0.6 0.6 2.9 Sphere + Ant 1957 Oct 4 214 938 65.10 LLEO/I -
S00003 00003 1957 BET 1 P A 2-y ISZ PS-2 1957 Nov 3 A00002 1957 Nov 3 0235 Earth 1958 Apr 14 0200? AR - OKB1 SU OKB1 PS - 508 508 8308 ? 2.0 1.0 2.0 Cone 1957 Nov 3 211 1659 65.33 LEO/I -
S00004 00004 1958 ALP P A Explorer 1 Explorer 1 1958 Feb 1 A00004 1958 Feb 1 0355 Earth 1970 Mar 31 1045? AR - ABMA/JPL US JPL Explorer - 8 8 14 0.8 0.1 0.8 Cyl 1958 Feb 1 359 2542 33.18 LEO/I -
S00005 00005 1958 BET 2 P Vanguard I Vanguard Test Satellite 1958 Mar 17 S00016 1958 Mar 17 1224 Earth - O - NRL US NRL NRL 6" - 2 2 2 0.1 0.1 0.1 Sphere 1959 May 23 657 3935 34.25 MEO -
S00006 00006 1958 GAM P A Explorer 3 Explorer 3 1958 Mar 26 A00005 1958 Mar 26 1745 Earth 1958 Jun 28 AR - ABMA/JPL US JPL Explorer - 8 8 14 0.8 0.1 0.8 Cyl 1958 Mar 26 195 2810 33.38 LEO/I -
S00007 00007 1958 DEL 1 R2 8K74A 8K74A 1958 May 15 - 1958 May 15 0705 Earth 1958 Dec 3 R - OKB1 SU OKB1 Blok-A - 7790 7790 7820 ? 28.0 2.6 28.0 Cyl 1958 May 15 214 1860 65.18 LEO/I -
S00008 00008 1958 DEL 2 P 3-y Sovetskiy ISZ D-1 No. 2 1958 May 15 S00007 1958 May 15 0706 Earth 1960 Apr 6 R - OKB1 SU OKB1 Object D - 1327 1327 1327 3.6 1.7 3.6 Cone 1959 May 7 207 1247 65.12 LEO/I -
S00009 00009 1958 EPS P A Explorer 4 Explorer 4 1958 Jul 26 A00009 1958 Jul 26 1507 Earth 1959 Oct 23 AR - ABMA/JPL US JPL Explorer - 12 12 17 0.8 0.1 0.8 Cyl 1959 Apr 24 258 2233 50.40 LEO/I -
S00010 00010 1958 ZET P A SCORE SCORE 1958 Dec 18 A00015 1958 Dec 18 2306 Earth 1959 Jan 21 AR - ARPA/SRDL US SRDL SCORE - 68 68 3718 2.5 ? 1.5 ? 2.5 Cone 1958 Dec 30 159 1187 32.29 LEO/I -
S00011 00011 1959 ALP 1 P Vanguard II Cloud cover satellite 1959 Feb 17 S00012 1959 Feb 17 1605 Earth - O - BSC US NRL NRL 20" - 10 10 10 0.5 0.5 0.5 Sphere 1959 May 15 564 3304 32.88 MEO -
S00012 00012 1959 ALP 2 R3 GRC 33-KS-2800 GRC 33-KS-2800 175-15-21 1959 Feb 17 R02749 1959 Feb 17 1604 Earth - O - BSC US GCR 33-KS-2800 - 195 22 22 1.5 0.7 1.5 Cyl 1959 Apr 28 564 3679 32.88 MEO -
S00013 00013 1959 BET P A Discoverer 1 CORONA Test Vehicle 2 1959 Feb 28 A00017 1959 Feb 28 2156 Earth 1959 Mar 5 AR - ARPA/CIA US LMSD CORONA - 78 ? 78 ? 668 ? 2.0 1.5 2.0 Cone 1959 Feb 28 163? 968? 89.70 LLEO/P -
S00014 00014 1959 GAM P A Discoverer 2 CORONA BIO 1 1959 Apr 13 A00021 1959 Apr 13 2126 Earth 1959 Apr 26 AR - ARPA/CIA US LMSD CORONA - 110 ? 110 ? 788 1.3 1.5 1.3 Frust 1959 Apr 13 239 346 89.90 LLEO/P -
S00015 00015 1959 DEL 1 P Explorer 6 NASA S-2 1959 Aug 7 S00017 1959 Aug 7 1430 Earth 1961 Jul 1 R? - GSFC US TRW Able Probe ARC 420 40 40 42 ? 0.7 0.7 2.2 Sphere + 4 Pan 1959 Sep 8 250 42327 46.95 HEO - Able 3
S00016 00016 1958 BET 1 R3 GRC 33-KS-2800 GRC 33-KS-2800 144-79-22 1958 Mar 17 R02064 1958 Mar 17 1223 Earth - O - NRL US GCR 33-KS-2800 - 195 22 22 1.5 0.7 1.5 Cyl 1959 Sep 30 653 4324 34.28 MEO -
S00017 00017 1959 DEL 2 R3 Altair Altair X-248 1959 Aug 7 A00024 1959 Aug 7 1428 Earth 1961 Jun 30 R? - USAF US ABL Altair - 24 24 24 1.5 0.5 1.5 Cyl 1961 Jan 8 197 40214 47.10 GTO -
S00018 00018 1959 EPS 1 P A Discoverer 5 CORONA C-2 1959 Aug 13 A00028 1959 Aug 13 1906 Earth 1959 Sep 28 AR - ARPA/CIA US LMSD CORONA - 140 140 730 1.3 1.5 1.3 Frust 1959 Aug 14 215 732 80.00 LLEO/I - NRO Mission 9002
推荐答案
一种不太偶然的方法是将第一行的标题解释为列指示符，并在这些宽度上进行拆分.
A less haphazard approach would be to interpret the headers on the first line as column indicators, and split on those widths.
import sys
import re
def col_widths(s):
# Shamelessly adapted from https://stackoverflow.com/a/33090071/874188
cols = re.findall(r'\S+\s+', s)
return [len(col) for col in cols]
widths = col_widths(next(sys.stdin))
for line in sys.stdin:
line = line.rstrip('\n')
fields = []
for col_max in widths[:-1]:
fields.append(line[0:col_max].strip())
line = line[col_max:]
fields.append(line)
print(fields)
这似乎可以更好地解释例如 LDate 列，其中有时用多个空格填充日期.倒数第二列将最后的破折号保留为列值的一部分；这似乎更符合原始表的作者的意图，但如果您不喜欢，也许可以将其与该特定列分开.
This seems to provide a better interpretation of e,g. the LDate column, where the dates are sometimes padded with more than one space. The penultimate column preserves the final dash as part of the column value; this seems more consistent with the apparent intent of the author of the original table, though perhaps separately split that off from that specific column if that's not to your liking.
如果您不想阅读 sys.stdin ，只需将其包装在中，并用open(filename)作为句柄:并替换 sys.stdin 随处带有 handle .
If you don't want to read sys.stdin, just wrap this in with open(filename) as handle: and replace sys.stdin with handle everywhere.
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