Created
July 19, 2022 22:28
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Get last line of file (csv) without reading the entire file into memory
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#This works. Yields the last line of the file as a string without reading the entire file into memory. | |
#Use a parsing function to separate returned data by commas to select the desired element. | |
import os | |
def get_last_line_records_of_file(identifier_data): | |
filepath = linux_path+"/"+identifier_data+".csv" | |
try: | |
with open(filepath,'rb') as f: | |
f.seek(-1,os.SEEK_END) | |
text = [f.read(1)] | |
while text[-1] != '\n'.encode('utf-8') or len(text)==1: | |
f.seek(-2, os.SEEK_CUR) | |
text.append(f.read(1)) | |
except Exception as e: | |
print("EXCEPTION: ",e) | |
pass | |
return ''.join([t.decode('utf-8') for t in text[::-1]]).strip() |
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Ever want to get the last record in a csv dataset without reading in the entire dataset? Dataset too big to fit into memory? Just need to know the date of the last record to know where to append next? You're welcome. Solution not by me but via stack overflow adapted for my needs.