Reading in multiple files in Python and saving them one by one in a different directory - python-3.x

Question

import glob
import pandas as pd
import seaborn as sns
import numpy as np
from scipy import signal
import matplotlib.pyplot as plt
files = glob.glob("Angular_position_*_*.csv")
output = pd.DataFrame()
for f in files:
df = pd.read_csv(f)
time = df.iloc[:,0]
time = time.to_numpy()
ynew = df.iloc[:,1:]
ynew = ynew.to_numpy()
lowPassCutoffFreq = 6.0 # Cut off frequency
Sample_freq = 150; #Target sample frequency
N = 2 # Order of the filter; In this case 2nd order
Wn = lowPassCutoffFreq/(Sample_freq/2) #Normalize frequency
b, a = signal.butter(5, Wn, btype='low',analog=False,output='ba')
#scipy.signal.butter(N, Wn, btype='low', analog=False, output='ba', fs=None)
output = signal.filtfilt(b, a, ynew, axis=0)
np.savetxt("enter directory path/Filtered_files/Filtered_Angular_position_*_*", output, delimiter = ', ', newline = "\n")
I am trying to read in all files in a directory, they are then low pass filtered. After that the results are saved one after the other but not in one file. The result gives each files with 3 columns and ideally I would like them to named with headers e.g. col1, col2, col3.
Without using glob, I can filter all my files individually but I have more than 100 such files.
Any help would be appreciated.
best wishes,

Answer 1

I have partially solved the issue apart from the header names:
import glob
import pandas as pd
from tnorma import tnorma
import seaborn as sns
import numpy as np
from scipy import signal
import matplotlib.pyplot as plt
path = r'location_of_dir'
all_files = glob.glob(path + '/*.csv')
# yn = np.zeros(shape = (101,1))
# tn = np.zeros(shape = (101,1))
#ynew = []
yn = np.zeros(shape = (101,1))
for filename in all_files:
df = pd.read_csv(filename, index_col=None, header=0)
print(filename)
foo = filename.split("/")[-1]
#df = pd.read_csv(f)
time = df.iloc[:,0]
time = time.to_numpy()
ynew = df.iloc[:,1:]
ynew = ynew.to_numpy()
#print(ynew)
lowPassCutoffFreq = 6.0 # Cut off frequency
Sample_freq = 150; #Target sample frequency
N = 2 # Order of the filter; In this case 2nd order
Wn = lowPassCutoffFreq/(Sample_freq/2) #Normalize frequency
b, a = signal.butter(5, Wn, btype='low',analog=False,output='ba')
#scipy.signal.butter(N, Wn, btype='low', analog=False, output='ba', fs=None)
output = signal.filtfilt(b, a, ynew, axis=0)
#print (output)
tn = np.linspace(0, 100, 101) # new time vector for the new time-normalized data
yn, tn, indie = tnorma(output, k=3, smooth =1, mask = None, show = False)
np.savetxt("path_name/foldername/file"+ foo, yn, delimiter = ', ', newline = "\n")
However, I am having difficulty in putting header names on the 3 columns per file.