Python，Pandas。 从特定列创建文本文件

Question

I am trying to create a text file from a column in a pandas dataframe. There are repeating values and I'd like each value to only be copied once. I also do not want the row value in the text file.

I have tried creating a dictionary:

stocks = dict(enumerate(df.tic.unique()))

then:

f = open("stocks","w")
f.write( str(stocks) )
f.close()

The text file output is all the names, but I'd like each to have their own line. Additionally, the row number is included which I need left out.

Answer 1

You're writing the string 'stocks' to the file. You need to write the variable stocks .

saveFile = open('stocks', 'w')
saveFile.write(stocks)
saveFile.close()

Answer 2

I don't know what your dataframe looks like but here's an example.

d = {'col1': [1, 2, 3], 'col2': [4, 5, 6]}
df = pd.DataFrame(d)
df["col1"].to_csv(r'data.txt', header=None, index=None, sep='\t', mode='a')

Replace the col1 in df["col1"] with the name of your column and df by the name of your dataframe of course. IF you want to remove duplicates you could also simply use df.drop_duplicate(...) with the settings you want before saving your dataframe in the text file.

Answer 3

If you want to use unique() , you can try this:

with open("stocks.txt", "w") as f:
    f.write("\n".join(df.tic.unique()))

1. df.tic.unique() returns the unique values of the column tic
2. "\n".join(df.tic.unique()) concatenates the unique values into a giant string, separated by new-line
3. f.write writes the giant string from 2 to the file

I have also edited "stocks" to "stocks.txt" .