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Pandas functions to read .CSV files before / after an empty line is encountered.
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# Python functions to read .CSV files into a Pandas DataFrame when the data of interest is before / after one or more empty/blank lines. | |
def csv_after_emptylines(filepath, bl_group_n=1, dtype=str): | |
""" Read a .CSV into a Pandas DataFrame, but only after at least one blank line has been skipped. | |
bl_group_n is the expected number of distinct blocks of blank lines (of any number of rows each) to skip before reading data. | |
NB: E.g. pd.read_csv(filepath, skiprows=[0, 1, 2]) works if you know the number of rows to be skipped. Use this function if you have a variable / unknown number of filled rows (to be skipped / ignored) before the empty rows. | |
""" | |
with open(filepath, newline='') as f: | |
blank_lines = 0 | |
bl_groups = 0 | |
contents = [] | |
headers = None | |
r = csv.reader(f) | |
for i, l in enumerate(r): | |
if bl_groups < bl_group_n: | |
if not l: | |
blank_lines += 1 | |
continue | |
if blank_lines == 0: | |
continue | |
bl_groups += 1 | |
blank_lines = 0 | |
headers = l | |
continue | |
contents.append(l) | |
return pd.DataFrame(data=contents, columns=headers, dtype=dtype) | |
def csv_until_emptyline(filepath, dtype=str): | |
""" Read a .CSV into a Pandas DataFrame until a blank line is found, then stop. | |
""" | |
with open(filepath, newline='') as f: | |
contents = [] | |
r = csv.reader(f) | |
for i, l in enumerate(r): | |
if not l: | |
break | |
if i == 0: | |
headers = l | |
continue | |
contents.append(l) | |
return pd.DataFrame(data=contents, columns=headers, dtype=dtype) |
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