def load_compustat(
freq,
get=['sale'],
debug=False,
comp_dir=r'C:\Users\derobertisna.UFAD\Desktop\Data\Compustat'):
freq = check_freq(freq)
name = freq_to_name(freq, debug)
path = os.path.join(comp_dir, name)
comp = load_sas(path, dtype={'gvkey': str})
comp = keep_relevant_data_compustat(comp, get=get, freq=freq)
convert_date_compustat(comp)
return comp
def _load_data_by_extension_and_convert_date(filepath, freq='m'):
filename, file_extension = os.path.splitext(filepath)
extension = file_extension.lower()
if extension == '.sas7bdat':
df = load_sas(filepath)
if freq != 'm':
df['date'] = convert_sas_date_to_pandas_date(
df['date']) #convert to date object
return df
elif extension == '.csv':
if freq != 'm':
return pd.read_csv(filepath, parse_dates=['date'])
else:
return pd.read_csv(filepath)
else:
raise ValueError(
f'Please pass a sas7bdat or csv for FF factors, got {extension}')
def __load_crsp(self):
#Check frequency
if self.freq.lower() == 'm':
filename = 'msf'
elif self.freq.lower() == 'd':
filename = 'dsf'
else:
raise ValueError('use m or d for frequency')
if self.debug:
filename += '_test' #debug datasets only have permnos 10516, 10517
#Load in CRSP file
self._log('Loading CRSP dataframe...')
filepath = os.path.join(self.crsp_dir, filename + '.sas7bdat')
self.crsp_dfs[self.freq.lower()] = load_sas(filepath)
self._log('Loaded.')
#Change date to datetime format
self._log('Converting SAS date to Pandas format.')
self.crsp_dfs[
self.freq.lower()]['DATE'] = convert_sas_date_to_pandas_date(
self.crsp_dfs[self.freq.lower()]['DATE'])
self._log('Converted.')
def merge_dsenames(df,
on='TICKER',
get='PERMNO',
date='Date',
other_byvars=None,
crsp_dir=None):
'''
Merges with dsenames file on on variable (TICKER, PERMNO, PERMCO, NCUSIP, CUSIP6), to get get variable (same list).
Must have a Date variable in df.
Default is to match on TICKER and pull PERMNO.
Required inputs:
df: pandas dataframe containing any of (TICKER, PERMNO, PERMCO, NCUSIP, CUSIP6)
Optional inputs:
on: str, column name to merge on, one of (TICKER, PERMNO, PERMCO, NCUSIP, CUSIP6)
get: str or list, column or columns to get from dsenames, any of (TICKER, PERMNO, PERMCO, NCUSIP, CUSIP6)
that aren't already in on
date: str, column name of date variable
other_byvars: any other variables signifying groups in the data, prevents from collapsing those groups
'''
# Set default CRSP dir
# if crsp_dir is None:
# crsp_dir = data_path('CRSP')
#Make get a list
if isinstance(get, str):
get = [get]
assert isinstance(get, list)
#Make other byvars a list
if not other_byvars:
other_byvars = []
if isinstance(other_byvars, str):
other_byvars = [other_byvars]
assert isinstance(other_byvars, list)
assert on not in get #can't get what we already have
#Pull from CRSP dsenames file
file = 'dsenames'
fullpath = os.path.join(crsp_dir, file + '.sas7bdat')
names_df = load_sas(fullpath)
#Convert NCUSIP to CUSIP6
if on == 'CUSIP6' or 'CUSIP6' in get:
names_df['CUSIP6'] = names_df['NCUSIP'].apply(
lambda x: x if pd.isnull(x) else x[:6])
names_df['start'] = convert_sas_date_to_pandas_date(names_df['NAMEDT'])
names_df['end'] = convert_sas_date_to_pandas_date(names_df['NAMEENDT'])
names_df['end'] = names_df['end'].fillna(datetime.date.today())
#Now perform merge
merged = df[[on, date] + other_byvars].merge(
names_df[['start', 'end', on] + get], how='left', on=on)
#Drop out observations not in name date range
valid = (merged[date] >= merged['start']) & (merged[date] <= merged['end'])
#However if there is not a match, doing merged[valid] would drop the observation instead of leaving nan
#Therefore, take merged[valid] and merge back again to original
new_merged = df.merge(merged[valid].drop(['start', 'end'], axis=1),
how='left',
on=[on, date] + other_byvars)
new_merged = new_merged.reset_index(drop=True)
if 'PERMNO' in get:
#Dsenames has no record of which permno is the primary link when a firm has multiple share classes.
#To get this information, we must merge ccmxpf_linktable. We want to keep only primary links.
dups = new_merged[[date, on] + other_byvars].duplicated(
keep=False) #series of True or False of whether duplicated row
if dups.any(
): #this means we got more than one permno for a single period/firm/byvars
duplicated = new_merged[dups].reset_index(
) #puts index in a column for later use
not_duplicated = new_merged[~dups]
#Take duplicated, merge to ccmxpf_linktable to get gvkey, and the ones which do not have gvkeys are
#the non-primary links
with_gvkey = get_gvkey_or_permno(
duplicated, date) #default is to get gvkey with permno
removed_duplicates = with_gvkey[~pd.isnull(with_gvkey['GVKEY']
)].drop('GVKEY', axis=1)
#Set index back
removed_duplicates.set_index('index', inplace=True)
#Now append back together and sort
full = not_duplicated.append(removed_duplicates)
new_merged = full.sort_index()
return new_merged.reset_index(drop=True)
def get_gvkey_or_permno(df,
datevar,
get='GVKEY',
other_byvars=None,
crsp_dir=None):
"""
Takes a dataframe containing either GVKEY or PERMNO and merges to the CRSP linktable to get the other one.
"""
# Set default CRSP dir
# if crsp_dir is None:
# crsp_dir = data_path('CRSP')
if get == 'GVKEY':
rename_get = 'gvkey'
l_on = 'PERMNO'
r_on = 'lpermno'
elif get == 'PERMNO':
rename_get = 'lpermno'
l_on = 'GVKEY'
r_on = 'gvkey'
else:
raise ValueError('Need get="GVKEY" or "PERMNO"')
#Make other byvars a list
if not other_byvars:
other_byvars = []
if isinstance(other_byvars, str):
other_byvars = [other_byvars]
assert isinstance(other_byvars, list)
link_name = 'ccmxpf_linktable.sas7bdat'
link_path = os.path.join(crsp_dir, link_name)
link = load_sas(link_path)
link['linkdt'] = convert_sas_date_to_pandas_date(link['linkdt'])
link['linkenddt'] = convert_sas_date_to_pandas_date(link['linkenddt'])
#If end date is missing, that means link is still active. Make end date today.
link['linkenddt'] = link['linkenddt'].fillna(datetime.date.today())
#Remove links with no permno so that they don't match to nans in the input df
link.dropna(subset=['lpermno'], inplace=True)
merged = df.merge(
link[['lpermno', 'gvkey', 'linkdt', 'linkenddt', 'linkprim']],
how='left',
left_on=l_on,
right_on=r_on)
valid = (merged[datevar] >= merged.linkdt) & \
(merged[datevar] <= merged.linkenddt) & \
(merged.linkprim == 'P')
merged = merged[valid].drop(['linkdt', 'linkenddt', 'linkprim', r_on],
axis=1).drop_duplicates()
merged.rename(columns={rename_get: get}, inplace=True)
#Now merge back to the original again to ensure that rows are not deleted
new_merged = df.merge(merged[['PERMNO', 'GVKEY', datevar] + other_byvars],
how='left',
on=[l_on, datevar] + other_byvars)
return new_merged