使用 Python 计算文本文件中的列数 [英] Counting number of columns in text file with Python

问题描述

我有两个由空格分隔的列组成的文本文件.以下是这两个文件的摘录:

I have two text files composed of spaced-separated columns. These are excerpts of these two files:

文件A

 1 1742.420   -0.410  20.1530   0.4190   1.7080   0.5940
 2 1872.060    0.070  21.4710   0.2950   0.0670   0.3380
 3 1918.150    0.150  18.9220   0.0490   1.4240   0.1150
 4 1265.760    0.170  19.0850   0.0720   1.3330   0.1450
 5  308.880    0.220  20.5020   0.1570   0.0200   0.1720
 ....

文件B

 1 1198.367    6.465  15.684 0.015  3.119 0.140  1
 2 1451.023    6.722  17.896 0.031  0.171 0.041  1
 3 1032.364    6.788  18.895 0.074 -0.084 0.088  1
 4  984.509    7.342  19.938 0.171  0.043 0.322  1
 5 1068.536    7.369  19.182 0.091  0.486 0.143  1
 ....

如您所见，FileA 有 7 列，FileB 有 8 列.这是我用来计算列数的代码:

As you can see FileA has 7 columns and FileB has 8. This is the code I use to count the columns:

import csv
file = 'filename'
reader = csv.reader(file)
num_cols = 0
for col in reader:
    num_cols = num_cols + 1

这个小代码正确地给出了 FileA (7) 的列数，而不是 FileB(也给出了 7)这是怎么回事，我该如何解决?

This little code correctly gives the number of columns for FileA (7) but not for FileB (also gives 7) What's going on and how can I fix it?

如果我计算的是行数而不是列数，那么: 1- 我如何计算列数?和 2- 鉴于我的实际文件有数千行/行，为什么我会得到这些结果 (7)?

If I'm counting rows instead of columns then: 1- how can I count the columns? and 2- given that my actual files have several thousands of lines/rows, why am I getting these results (7)?

推荐答案

import csv

with open('filename') as f:
    reader = csv.reader(f, delimiter=' ', skipinitialspace=True)
    first_row = next(reader)
    num_cols = len(first_row)

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