我想将目录中的几个CSV文件读取到熊猫中,并将它们连接到一个大数据帧中。不过我没能弄清楚。这是我到目前为止所拥有的:
import glob
import pandas as pd
# Get data file names
path = r'C:DRODCL_rawdata_files'
filenames = glob.glob(path + "/*.csv")
dfs = []
for filename in filenames:
dfs.append(pd.read_csv(filename))
# Concatenate all data into one DataFrame
big_frame = pd.concat(dfs, ignore_index=True)
我想我需要在 for 循环中得到一些帮助?
请参阅 pandas:IO 工具了解所有可用方法。.read_
如果所有 CSV 文件都具有相同的列,请尝试以下代码。
我添加了 ,以便在读取 CSV 文件的第一行后,可以将其指定为列名。header=0
import pandas as pd
import glob
import os
path = r'C:DRODCL_rawdata_files' # use your path
all_files = glob.glob(os.path.join(path , "/*.csv"))
li = []
for filename in all_files:
df = pd.read_csv(filename, index_col=None, header=0)
li.append(df)
frame = pd.concat(li, axis=0, ignore_index=True)
或者,归因于 Sid 的评论。
all_files = glob.glob(os.path.join(path, "*.csv"))
df = pd.concat((pd.read_csv(f) for f in all_files), ignore_index=True)
pathlib
来自标准库将用于此示例。它将路径视为带有方法的对象,而不是要切片的字符串。from pathlib import Path
import pandas as pd
import numpy as np
path = r'C:DRODCL_rawdata_files' # or unix / linux / mac path
# Get the files from the path provided in the OP
files = Path(path).glob('*.csv') # .rglob to get subdirectories
dfs = list()
for f in files:
data = pd.read_csv(f)
# .stem is method for pathlib objects to get the filename w/o the extension
data['file'] = f.stem
dfs.append(data)
df = pd.concat(dfs, ignore_index=True)
enumerate
dfs = list()
for i, f in enumerate(files):
data = pd.read_csv(f)
data['file'] = f'File {i}'
dfs.append(data)
df = pd.concat(dfs, ignore_index=True)
np.repeat
[f'S{i}' for i in range(len(dfs))]
创建字符串列表以命名每个数据帧。[len(df) for df in dfs]
创建长度列表# Read the files into dataframes
dfs = [pd.read_csv(f) for f in files]
# Combine the list of dataframes
df = pd.concat(dfs, ignore_index=True)
# Add a new column
df['Source'] = np.repeat([f'S{i}' for i in range(len(dfs))], [len(df) for df in dfs])
.assign
df = pd.concat((pd.read_csv(f).assign(filename=f.stem) for f in files), ignore_index=True)
或
df = pd.concat((pd.read_csv(f).assign(Source=f'S{i}') for i, f in enumerate(files)), ignore_index=True)
darindaCoder的答案的替代方案:
path = r'C:DRODCL_rawdata_files' # use your path
all_files = glob.glob(os.path.join(path, "*.csv")) # advisable to use os.path.join as this makes concatenation OS independent
df_from_each_file = (pd.read_csv(f) for f in all_files)
concatenated_df = pd.concat(df_from_each_file, ignore_index=True)
# doesn't create a list, nor does it append to one
import glob
import os
import pandas as pd
df = pd.concat(map(pd.read_csv, glob.glob(os.path.join('', "my_files*.csv"))))
模板简介:该模板名称为【Python将多个CSV文件导入熊猫并连接成一个数据帧】,大小是暂无信息,文档格式为.编程语言,推荐使用Sublime/Dreamweaver/HBuilder打开,作品中的图片,文字等数据均可修改,图片请在作品中选中图片替换即可,文字修改直接点击文字修改即可,您也可以新增或修改作品中的内容,该模板来自用户分享,如有侵权行为请联系网站客服处理。欢迎来懒人模板【Python】栏目查找您需要的精美模板。