擅长:python、mysql、java
<p>您必须将任务分为三个步骤:
1读取CSV文件
2生成新列的值
三。为文件添加价值
导入csv
导入文件输入
导入系统</p>
<pre><code># 1. Read CSV file
# This is opening CSV and reading value from it.
with open("dev.csv") as filein:
reader = csv.reader(filein, skipinitialspace = True)
xs, ys = zip(*reader)
result=["Total_GeneralID"]
# 2. Generate new column's value
# This loop is for counting the "GeneralID" element.
for i in range(1,len(ys),1):
result.append(ys.count(ys[i]))
# 3. Add value to the file back
# This loop is for writing new column
for ind,line in enumerate(fileinput.input("dev.csv",inplace=True)):
sys.stdout.write("{} {}, {}\n".format("",line.rstrip(),result[ind]))
</code></pre>
<p>我没有使用临时文件或任何高级模块,如熊猫或任何东西。在</p>