boolean

问题 if ((vnd = (struct diam_vnd_t *)g_hash_table_lookup(vendors,vend))) {...} Can you tell me why it is an assignment but not a boolean expression in the brackets ? And in what situation this assignment can be considered "true" or "false" ? 回答1: Quoting C11 , chapter §6.5.16, Assignment operators ( emphasis mine ) An assignment operator stores a value in the object designated by the left operand. An assignment expression has the value of the left operand after the assignment, 111) but is not an

问题 if ((vnd = (struct diam_vnd_t *)g_hash_table_lookup(vendors,vend))) {...} Can you tell me why it is an assignment but not a boolean expression in the brackets ? And in what situation this assignment can be considered "true" or "false" ? 回答1: Quoting C11 , chapter §6.5.16, Assignment operators ( emphasis mine ) An assignment operator stores a value in the object designated by the left operand. An assignment expression has the value of the left operand after the assignment, 111) but is not an

问题 I have a pandas data frame (v 0.20.3): df = pd.DataFrame({'coname1': ['Apple','Yahoo'], 'coname2':['Apple', 'Google']}) df['eq'] = df.apply(lambda row: row['coname1'] == row['coname2'], axis=1).astype(bool) coname1 coname2 eq 0 Apple Apple True 1 Yahoo Google False If I would like to replace True/False to 'Yes'/'No' , I could run this: df.replace({ True: 'Yes', False: 'No' }) coname1 coname2 eq 0 Apple Apple Yes 1 Yahoo Google No Which seems to get the job done. However, if a data frame is

来源： https://stackoverflow.com/questions/27853301/do-not-understand-why-if-condition-evaluates-to-true-when-variable-is-integer

来源： https://stackoverflow.com/questions/36280274/php-if-true-test-on-array-always-returns-true

来源： https://stackoverflow.com/questions/44773017/errorcan-only-compare-identically-labeled-series-objects-and-sort-index

来源： https://stackoverflow.com/questions/40432805/how-is-true-2-implemented

来源： https://stackoverflow.com/questions/40432805/how-is-true-2-implemented

来源： https://stackoverflow.com/questions/40432805/how-is-true-2-implemented

来源： https://stackoverflow.com/questions/40432805/how-is-true-2-implemented