擅长:python、mysql、java
<p>如果我很理解你的问题,这个脚本应该可以:</p>
<pre class="lang-py prettyprint-override"><code>input_file = 'wk.csv'
output_file = 'new_wk.csv'
# Reading input
f = open(input_file, 'r')
rows = f.read().split('\n')
if '' in rows: # remove last blank line if needed
rows.remove('')
f.close()
# Writing output
f = open(output_file, 'w')
for row in rows: # loop over your million rows
print(row)
x, y, z = row.split(' ')
z = '-'+z # editing z
f.write('{} {} {}\n'.format(x, y, z))
f.close()
</code></pre>