問(wèn)題描述
我有一個(gè)包含數(shù)值的 csv 文件，例如 1524.449677.總有 6 位小數(shù).
I have a csv file containing numerical values such as 1524.449677. There are always exactly 6 decimal places.
當(dāng)我通過(guò) pandas read_csv 導(dǎo)入 csv 文件(和其他列)時(shí)，該列會(huì)自動(dòng)獲取數(shù)據(jù)類型 object.我的問(wèn)題是這些值顯示為 2470.6911370000003 實(shí)際上應(yīng)該是 2470.691137.或者值 2484.30691 顯示為 2484.3069100000002.
When I import the csv file (and other columns) via pandas read_csv, the column automatically gets the datatype object. My issue is that the values are shown as 2470.6911370000003 which actually should be 2470.691137. Or the value 2484.30691 is shown as 2484.3069100000002.
這在某種程度上似乎是一個(gè)數(shù)據(jù)類型問(wèn)題.在通過(guò) read_csv 導(dǎo)入時(shí)，我嘗試通過(guò)將 dtype 參數(shù)作為 {'columnname': np.float64} 來(lái)顯式提供數(shù)據(jù)類型.問(wèn)題仍然沒(méi)有消失.
This seems to be a datatype issue in some way. I tried to explicitly provide the data type when importing via read_csv by giving the dtype argument as {'columnname': np.float64}. Still the issue did not go away.
如何獲取導(dǎo)入的值并完全按照它們?cè)谠?csv 文件中的樣子顯示?
How can I get the values imported and shown exactly as they are in the source csv file?
推薦答案
Pandas 使用專用的 dec 2 bin 轉(zhuǎn)換器，該轉(zhuǎn)換器會(huì)犧牲準(zhǔn)確性而不是速度.
Pandas uses a dedicated dec 2 bin converter that compromises accuracy in preference to speed.
將 float_precision='round_trip' 傳遞給 read_csv 可以解決此問(wèn)題.
Passing float_precision='round_trip' to read_csv fixes this.
查看 此頁(yè)面 了解更多詳情.
Check out this page for more detail on this.
處理完你的數(shù)據(jù)后，如果你想把它保存回一個(gè)csv文件，你可以將float_format = "%.nf"傳給對(duì)應(yīng)的方法.
After processing your data, if you want to save it back in a csv file, you can passfloat_format = "%.nf" to the corresponding method.
一個(gè)完整的例子:
import pandas as pd
df_in = pd.read_csv(source_file, float_precision='round_trip')
df_out = ... # some processing of df_in
df_out.to_csv(target_file, float_format="%.3f") # for 3 decimal places
這篇關(guān)于Pandas 讀取具有浮點(diǎn)值的 csv 文件會(huì)導(dǎo)致奇怪的舍入和小數(shù)位數(shù)的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！